[16] Centre-left in orientation,[17] the group mostly comprises social democratic parties and is affiliated with the Progressive Alliance and Socialist International.

[3] In 1999, the Parliament refused to approve the Santer Commission's handling of the EU budget.

Allegations of corruption centred on two PES Commissioners, Édith Cresson and Manuel Marín.

The group sought additional members in the Democratic Party of Italy, which was not affiliated to the PES in 2009.

[25][26] By the conclusion of the 2004–2009 parliamentary term, the Democratic Party had 8 MEPs in the Socialist Group (coming from the Democrats of the Left), but also had eight MEPs in ALDE Group (coming from the Daisy).

The Democratic Party is a big tent centre-left party, strongly influenced by social democracy and the Christian left, and had MEPs who were former Christian Democrats or had other political views.

[1] The S&D Group joined the Progressive Alliance upon its official foundation on 22 May 2013[35] and is a member of the organisation's board.

As a consequence of Brexit, British S&D Member Claude Moraes had to resign from his position as vice-president.