As MPs returned to work after a two-week break Monday, the NDP learned that Bruce Hyer has left caucus to sit as an Independent.

Hyer, MP for Thunder Bay-Superior North, said that while he has "much respect for most Members in this House," he criticized what he called "mindless solidarity, where political parties are always right and voters are always wrong."

Hyer broke ranks with the NDP on the recent gun registry vote, siding with the Tories to scrap the registry.

In a statement posted to his website, Hyer cited the registry debate as an example of an issue "where there has been no real compromise at all."

In his statement, Hyer criticized NDP Leader Thomas Mulcair for wanting to bring back the registry and indicating he would whip the vote to do so. Hyer also said he was "concerned that Mr. Mulcair does not seem willing to co-operate with other parties on important issues."

Hyer was left out of the NDP's shadow cabinet when it was announced last week. He said he took that as "a clear message that my constituents will be muzzled.

"As an Independent voice, I will better be able to represent my constituents in Parliament," he said.

"I will focus on doing what I have worked hard to do for over three years: Help the people being mistreated by federal agencies. Work with all parties or MPs when possible to make Parliament work. And speak up inside and outside the House for issues important for Northwestern Ontario, and Canada."

CTV News Channel's Mercedes Stephenson tweeted Monday that Hyer will retain his NDP membership, but "will never again run for a political party that whips votes."

Mulcair said Monday that he found out about Hyer's decision "two minutes before Question Period," though he had known Hyer wanted more autonomy.

"I have nothing but good things to say about him as a person. But he's also made it very clear to me, as he did in writing during the campaign, that he doesn't accept the rule that caucuses or political parties can make decisions for the way we want to present ourselves to the public. He feels that MPs should be able to vote their own way, even on an important vote," Mulcair told CTV's Power Play.

"So I simply said to him that that's not going to be part of my plan. So he didn't get a position in the shadow cabinet. You can't give a person a shadow cabinet position if they're going to make up their own policies."

Mulcair said he does not intend to bring back the gun registry, but is working on a new policy. He did confirm that when that policy goes before the House, he will whip the vote.

Hyer's move leaves the NDP with 101 seats in the House of Commons. The Conservatives have 165 seats, the Liberals 35 seats, the Bloc Quebecois four seats, the Green Party one seat, and there are two Independents.

The other Independent MP is Peter Goldring of Edmonton East, who left the Tory caucus last December after being charged with refusing to blow into a breathalyzer.