Thailand's oldest political party has named Jurin Laksanawisit as its new leader following its abysmal performance in recent elections that led to the resignation of its previous chief.

The vote on Wednesday by members of the Democrat Party was to name a successor to Abhisit Vejjajiva, a former prime minister who resigned as leader when results were released from the March 24 general election. Jurin has served in the Cabinets of two Democrat-led governments.

The party, founded in 1946, finished fourth in the election as voters in its Bangkok and southern strongholds deserted it. Its supporters apparently switched their allegiance to a military-backed party that supports the return to the prime minister's office of former army commander Prayuth Chan-ocha, who came to power by staging a military coup in 2014.