European political parties were first mentioned in the 1992 Treaty of Maastricht, stating that "Political parties at European level are important as a factor for integration within the Union.
Regulation 2004/2003 provided the first official definition of European political parties and created a framework for their public funding.
In 2007, Regulation 1524/2007 updated modalities for the funding of European parties and allowed them to set up affiliated European political foundations, separate entities contributing to the debate on European issues, organising conferences, and carrying out research, and linking like-minded national political foundations.
In May 2018, the European Parliament and the Council adopted Regulation 2018/673, which amended Regulation 1141/2014 by detailing provisions relating to the registration of political parties and foundations, and transparency regarding political programmes and party logos.
Great ideological diversity can be found in most European political alliances, and individual country rows may not correspond with the heuristic left-right spectrum commonly used within its own political discourse.