Quebec's most popular political party has officially joined forces with another, smaller party – the Action démocratique du Québec.

Members of the ADQ voted to approve the merger with the new Coalition Avenir Québec (CAQ), which promises to set aside the debate on sovereignty.

Results of the vote were released Sunday morning.

The ADQ has been around for two decades but has struggled in recent years.

The merger means the Coalition gets the ADQ's four seats in the Quebec legislature.

An agreement in principle was reached between the parties in December but ADQ members had the final say in a mail-in ballot.

Just over 70 per cent of those who voted approved the deal.

The Coalition has been ahead of the ruling Liberals and the Opposition Parti Québécois in public opinion polls for several months, even before it became an official party.

The Coalition, led by former PQ cabinet minister François Legault, was originally billed as right wing but shifted more to the centre in developing its platform.

The ADQ took more conservative positions over the years, such as endorsing private health care and school vouchers.

With files from the Canadian Press