The Quebec Liberals have named longtime member Pierre Arcand as their interim leader.

Arcand was chosen by the party's caucus today to lead the Opposition in the legislature.

He takes over from Philippe Couillard, the outgoing premier who resigned his seat and quit as party leader Thursday.

Couillard's departure followed a resounding Liberal election defeat Monday at the hands of Francois Legault's Coalition Avenir Quebec.

Arcand, first elected in 2007, is a former cabinet minister representing the Montreal riding of Mont-Royal-Outremont.

He says details of the race to find a permanent leader will be finalized in the coming months.

The party also announced that longtime member Guy Ouellette has been excluded from caucus following a revelation during the campaign that in 2016 he had fed the Coalition incriminating information about a Liberal political appointee.

Arcand says Ouellette was offered an opportunity to explain himself to caucus members, but he chose to send a letter instead.