The BC Liberals have taken action to remove Darryl Plecas from their party after he accepted an offer to Serve as Speaker of the House under a New Democrat government, strengthening the BC NDP's political position.

Plecas' move to become speaker gives some breathing room to the NDP's razor-thin minority government. But goes against the Liberal party's wishes.

"Yesterday in Victoria, that trust was broken when the MLA for Abbotsford South accepted the opportunity to serve as Speaker of the House, despite repeated promises and assurances that he would not do so," Sharon White, president of the BC Liberals, said in a statement to party members Saturday.

White says the Liberas have revoked Plecas' membership in the party, which she says is "the strongest action available to us."

Earlier Friday, interim Liberal Leader Rich Coleman said Plecas betrayed his own party and effectively joined the NDP by accepting the Speaker's post.

B.C. Premier John Horgan called Plecas's decision "an honourable thing."

The Liberals didn't warn Plecas about revoking his membership. He found out when a CTV News producer called him to ask for an interview moments after White sent the email to the party.

"I was actually quite surprised. I'm very disappointed," Plecas told CTV News.

Both the Greens and the NDP asked Plecas if he would consider being speaker a few months ago, and at that time Plecas turned them down.

But Plecas says he changed his mind after realizing an agreement by the NDP and the Greens to form government was, in his mind, legitimate.

Plecas' move effectively bolsters the NDP-Green government's thin grip on power by giving the Liberals one less vote and giving the premier a three-seat cushion.

With a report from CTV Vancouver's Scott Roberts and files from the Canadian Press.