The MDS remained illegal until 1981 when the more reform-minded Prime Minister Mohammed Mzali allowed oppositional parties to run candidates' lists in elections and announced to officially recognise them in case they won more than 5%.

Among the minor, weakly institutionalised oppositional parties, the MDS presented the most appealing candidates[citation needed] list and threatened to actually beat the PSD in the capital Tunis.

The MDS welcomed Zine El Abidine Ben Ali taking over the presidency from the longterm head of state Bourguiba in 1987.

[5] In 1994, a group of MDS dissidents around Mustapha Ben Jaafar founded the Democratic Forum for Labour and Liberties (FDTL), which was only legalised in 2002.

Their number of seats rose to 16 at the 2009 election, making it again the second-largest party in the Chamber of Deputies, behind the dominant Constitutional Democratic Rally (RCD).