The party was named after the Mahajana Eksath Peramuna (1956), an SLFP-led alliance which Gunawardena was a member of, after its disbandment that year.

In 1983, Dinesh Gunawardena became the common candidate to contest the Maharagama by-election on the MEP symbol, a cartwheel, winning with an overwhelming majority to become one of the 8 members of the opposition in the Sri Lankan Parliament.

In the 2004 Sri Lankan parliamentary elections, the party was part of the United People's Freedom Alliance, which won 45.6% of the popular vote and 105 out of 225 seats.

In 2019, the MEP joined the Sri Lanka People's Freedom Alliance, led by former president Mahinda Rajapaksa.

In the 2020 Sri Lankan parliamentary elections, the SLFPA won a landslide victory, winning 145 out of 225 seats of the Parliament.