diff --git a/src/app/main.cpp b/src/app/main.cpp
index d64a6aeef29b..53c1bd644258 100644
--- a/src/app/main.cpp
+++ b/src/app/main.cpp
@@ -1634,23 +1634,14 @@ int main( int argc, char *argv[] )
   {
     if ( !pythonfile.isEmpty() )
     {
-#ifdef Q_OS_WIN
-      //replace backslashes with forward slashes
-      pythonfile.replace( '\\', '/' );
-#endif
       pythonArgs.prepend( pythonfile );
     }
-
-    QgsPythonRunner::run( QStringLiteral( "sys.argv = ['%1']" ).arg( pythonArgs.replaceInStrings( QChar( '\'' ), QStringLiteral( "\\'" ) ).join( "','" ) ) );
+    QgsPythonRunner::setArgv( pythonArgs );
   }
 
   if ( !pythonfile.isEmpty() )
   {
-#ifdef Q_OS_WIN
-    //replace backslashes with forward slashes
-    pythonfile.replace( '\\', '/' );
-#endif
-    QgsPythonRunner::run( QStringLiteral( "with open('%1','r') as f: exec(f.read())" ).arg( pythonfile ) );
+    QgsPythonRunner::runFile( pythonfile );
   }
 
   /////////////////////////////////`////////////////////////////////////
diff --git a/src/app/qgisapp.cpp b/src/app/qgisapp.cpp
index 0d2bfecfc44a..16471e28c503 100644
--- a/src/app/qgisapp.cpp
+++ b/src/app/qgisapp.cpp
@@ -12101,6 +12101,20 @@ class QgsPythonRunnerImpl : public QgsPythonRunner
       return false;
     }
 
+    bool runFile( const QString &filename, const QString &messageOnError = QString() ) override
+    {
+#ifdef WITH_BINDINGS
+      if ( mPythonUtils && mPythonUtils->isEnabled() )
+      {
+        return mPythonUtils->runFile( filename, messageOnError );
+      }
+#else
+      Q_UNUSED( filename )
+      Q_UNUSED( messageOnError )
+#endif
+      return false;
+    }
+
     bool evalCommand( QString command, QString &result ) override
     {
 #ifdef WITH_BINDINGS
@@ -12115,6 +12129,20 @@ class QgsPythonRunnerImpl : public QgsPythonRunner
       return false;
     }
 
+    bool setArgv( const QStringList &arguments, const QString &messageOnError = QString() ) override
+    {
+#ifdef WITH_BINDINGS
+      if ( mPythonUtils && mPythonUtils->isEnabled() )
+      {
+        return mPythonUtils->setArgv( arguments, messageOnError );
+      }
+#else
+      Q_UNUSED( arguments )
+      Q_UNUSED( messageOnError )
+#endif
+      return false;
+    }
+
   protected:
     QgsPythonUtils *mPythonUtils = nullptr;
 };
diff --git a/src/core/qgspythonrunner.cpp b/src/core/qgspythonrunner.cpp
index 8dd7dab37ed1..91efbc620b39 100644
--- a/src/core/qgspythonrunner.cpp
+++ b/src/core/qgspythonrunner.cpp
@@ -39,6 +39,20 @@ bool QgsPythonRunner::run( const QString &command, const QString &messageOnError
   }
 }
 
+bool QgsPythonRunner::runFile( const QString &filename, const QString &messageOnError )
+{
+  if ( sInstance )
+  {
+    QgsDebugMsgLevel( "Running " + filename, 3 );
+    return sInstance->runFile( filename, messageOnError );
+  }
+  else
+  {
+    QgsDebugError( QStringLiteral( "Unable to run Python command: runner not available!" ) );
+    return false;
+  }
+}
+
 bool QgsPythonRunner::eval( const QString &command, QString &result )
 {
   if ( sInstance )
@@ -52,9 +66,21 @@ bool QgsPythonRunner::eval( const QString &command, QString &result )
   }
 }
 
+bool QgsPythonRunner::setArgv( const QStringList &arguments, const QString &messageOnError )
+{
+  if ( sInstance )
+  {
+    return sInstance->setArgv( arguments, messageOnError );
+  }
+  else
+  {
+    QgsDebugError( QStringLiteral( "Unable to run Python command: runner not available!" ) );
+    return false;
+  }
+}
+
 void QgsPythonRunner::setInstance( QgsPythonRunner *runner )
 {
   delete sInstance;
   sInstance = runner;
 }
-
diff --git a/src/core/qgspythonrunner.h b/src/core/qgspythonrunner.h
index 30920de902b8..560264fe69bf 100644
--- a/src/core/qgspythonrunner.h
+++ b/src/core/qgspythonrunner.h
@@ -32,7 +32,6 @@
 class CORE_EXPORT QgsPythonRunner
 {
   public:
-
     /**
      * Returns TRUE if the runner has an instance
      * (and thus is able to run commands)
@@ -42,9 +41,15 @@ class CORE_EXPORT QgsPythonRunner
     //! Execute a Python statement
     static bool run( const QString &command, const QString &messageOnError = QString() );
 
+    //! Execute a Python file
+    static bool runFile( const QString &filename, const QString &messageOnError = QString() );
+
     //! Eval a Python statement
     static bool eval( const QString &command, QString &result SIP_OUT );
 
+    //! Set sys.argv
+    static bool setArgv( const QStringList &arguments, const QString &messageOnError = QString() );
+
     /**
      * Assign an instance of Python runner so that run() can be used.
      * This method should be called during app initialization.
@@ -59,8 +64,12 @@ class CORE_EXPORT QgsPythonRunner
 
     virtual bool runCommand( QString command, QString messageOnError = QString() ) = 0;
 
+    virtual bool runFile( const QString &filename, const QString &messageOnError = QString() ) = 0;
+
     virtual bool evalCommand( QString command, QString &result ) = 0;
 
+    virtual bool setArgv( const QStringList &arguments, const QString &messageOnError = QString() ) = 0;
+
     static QgsPythonRunner *sInstance;
 };
 
diff --git a/src/python/qgspythonutils.h b/src/python/qgspythonutils.h
index 68bb9fc1490d..4f22592c4414 100644
--- a/src/python/qgspythonutils.h
+++ b/src/python/qgspythonutils.h
@@ -99,11 +99,23 @@ class PYTHON_EXPORT QgsPythonUtils
      */
     virtual QString runStringUnsafe( const QString &command, bool single = true ) = 0;
 
+    /**
+     * Runs a Python \a filename, showing an error message if one occurred.
+     * \returns TRUE if no error occurred
+     */
+    virtual bool runFile( const QString &filename, QString msgOnError = QString(), bool single = true ) = 0;
+
     /**
      * Evaluates a Python \a command and stores the result in a the \a result string.
      */
     virtual bool evalString( const QString &command, QString &result ) = 0;
 
+    /**
+     * Sets sys.argv to the given Python \a arguments, showing an error message if one occurred.
+     * \returns TRUE if no error occurred
+     */
+    virtual bool setArgs( const QStringList &arguments, QString msgOnError = QString(), bool single = true ) = 0;
+
     /**
      * Gets information about error to the supplied arguments
      * \returns FALSE if there was no Python error
diff --git a/src/python/qgspythonutilsimpl.cpp b/src/python/qgspythonutilsimpl.cpp
index 14facb8ea425..01b89318b17b 100644
--- a/src/python/qgspythonutilsimpl.cpp
+++ b/src/python/qgspythonutilsimpl.cpp
@@ -454,6 +454,132 @@ bool QgsPythonUtilsImpl::runString( const QString &command, QString msgOnError,
   return res;
 }
 
+QString QgsPythonUtilsImpl::runFileUnsafe( const QString &filename )
+{
+  // acquire global interpreter lock to ensure we are in a consistent state
+  PyGILState_STATE gstate;
+  gstate = PyGILState_Ensure();
+  QString ret;
+
+  QFile file( filename );
+  if ( !file.open( QIODevice::ReadOnly | QIODevice::Text ) )
+  {
+    ret = "Cannot open file";
+    goto error;
+  }
+
+  PyObject *obj = PyRun_String( file.readAll().constData(), Py_file_input, mMainDict, mMainDict );
+  PyObject *errobj = PyErr_Occurred();
+  if ( nullptr != errobj )
+  {
+    ret = getTraceback();
+  }
+  Py_XDECREF( obj );
+
+error:
+  // we are done calling python API, release global interpreter lock
+  PyGILState_Release( gstate );
+
+  return ret;
+}
+
+bool QgsPythonUtilsImpl::runFile( const QString &filename, const QString &messageOnError = QString() )
+{
+  const QString traceback = runFileUnsafe( filename );
+  if ( traceback.isEmpty() )
+    return true;
+
+  if ( msgOnError.isEmpty() )
+  {
+    // use some default message if custom hasn't been specified
+    msgOnError = QObject::tr( "An error occurred during execution of following file:" ) + "\n<tt>" + filename + "</tt>";
+  }
+
+  QString path, version;
+  evalString( QStringLiteral( "str(sys.path)" ), path );
+  evalString( QStringLiteral( "sys.version" ), version );
+
+  QString str = "<font color=\"red\">" + msgOnError + "</font><br><pre>\n" + traceback + "\n</pre>"
+                + QObject::tr( "Python version:" ) + "<br>" + version + "<br><br>"
+                + QObject::tr( "QGIS version:" ) + "<br>" + QStringLiteral( "%1 '%2', %3" ).arg( Qgis::version(), Qgis::releaseName(), Qgis::devVersion() ) + "<br><br>"
+                + QObject::tr( "Python path:" ) + "<br>" + path;
+  str.replace( '\n', QLatin1String( "<br>" ) ).replace( QLatin1String( "  " ), QLatin1String( "&nbsp; " ) );
+
+  qDebug() << str;
+  QgsMessageOutput *msg = QgsMessageOutput::createMessageOutput();
+  msg->setTitle( QObject::tr( "Python error" ) );
+  msg->setMessage( str, QgsMessageOutput::MessageHtml );
+  msg->showMessage();
+
+  return false;
+}
+
+QString QgsPythonUtilsImpl::setArgvUnsafe( const QStringList &arguments )
+{
+  // acquire global interpreter lock to ensure we are in a consistent state
+  PyGILState_STATE gstate;
+  gstate = PyGILState_Ensure();
+  QString ret;
+
+  PyObject *sysobj = nullptr, *argsobj = nullptr;
+  bool success = false;
+  sysobj = PyRun_String( "sys", Py_single_input, mMainDict, mMainDict );
+  if ( !sysobj )
+    goto error;
+  PyObject *argsobj = PyList_New( arguments.size() );
+  if ( !argsobj )
+    goto error;
+  for ( size_t i = 0; i != arguments.size(); ++i )
+  {
+    if ( PyList_SET_ITEM( argsobj, i, PyUnicode_FromString( arguments[i].toUtf8().constData() ) ) != 0 )
+      goto error;
+  }
+  if ( PyObject_SetAttrString( sysobj, "argv", argsobj ) != 0 )
+    goto error;
+  success = true;
+error:
+  Py_XDECREF( argsobj );
+  Py_XDECREF( sysobj );
+  if ( !success )
+    ret = "Cannot set sys.argv";
+
+  // we are done calling python API, release global interpreter lock
+  PyGILState_Release( gstate );
+
+  return ret;
+}
+
+bool QgsPythonUtilsImpl::setArgv( const QStringList &arguments, const QString &messageOnError = QString() )
+{
+  const QString traceback = setArgvUnsafe( arguments );
+  if ( traceback.isEmpty() )
+    return true;
+
+  if ( msgOnError.isEmpty() )
+  {
+    // use some default message if custom hasn't been specified
+    msgOnError = QObject::tr( "An error occurred while setting sys.argv from following list:" ) + "\n<tt>" + arguments.join( ',' ) + "</tt>";
+  }
+
+  QString path, version;
+  evalString( QStringLiteral( "str(sys.path)" ), path );
+  evalString( QStringLiteral( "sys.version" ), version );
+
+  QString str = "<font color=\"red\">" + msgOnError + "</font><br><pre>\n" + traceback + "\n</pre>"
+                + QObject::tr( "Python version:" ) + "<br>" + version + "<br><br>"
+                + QObject::tr( "QGIS version:" ) + "<br>" + QStringLiteral( "%1 '%2', %3" ).arg( Qgis::version(), Qgis::releaseName(), Qgis::devVersion() ) + "<br><br>"
+                + QObject::tr( "Python path:" ) + "<br>" + path;
+  str.replace( '\n', QLatin1String( "<br>" ) ).replace( QLatin1String( "  " ), QLatin1String( "&nbsp; " ) );
+
+  qDebug() << str;
+  QgsMessageOutput *msg = QgsMessageOutput::createMessageOutput();
+  msg->setTitle( QObject::tr( "Python error" ) );
+  msg->setMessage( str, QgsMessageOutput::MessageHtml );
+  msg->showMessage();
+
+  return false;
+}
+
 
 QString QgsPythonUtilsImpl::getTraceback()
 {
diff --git a/src/python/qgspythonutilsimpl.h b/src/python/qgspythonutilsimpl.h
index d900f1b55693..26ec410926e8 100644
--- a/src/python/qgspythonutilsimpl.h
+++ b/src/python/qgspythonutilsimpl.h
@@ -44,7 +44,11 @@ class QgsPythonUtilsImpl : public QgsPythonUtils
     bool isEnabled() final;
     bool runString( const QString &command, QString msgOnError = QString(), bool single = true ) final;
     QString runStringUnsafe( const QString &command, bool single = true ) final; // returns error traceback on failure, empty QString on success
+    bool runFile( const QString &filename, const QString &messageOnError = QString() ) final;
+    QString runFileUnsafe( const QString &filename ) final; // returns error traceback on failure, empty QString on success
     bool evalString( const QString &command, QString &result ) final;
+    QString setArgvUnsafe( const QStringList &arguments ) final; // returns error traceback on failure, empty QString on success
+    bool setArgv( const QStringList &arguments, const QString &messageOnError = QString() ) final;
     bool getError( QString &errorClassName, QString &errorText ) final;
 
     /**