Prime Minister Stephen Harper has signalled his plans to appoint three failed Conservative candidates to the Senate, including two who quit the upper chamber to run in the election.

Two of them, Larry Smith and Fabian Manning, are former senators who will be returning to the Red Chamber, and the other is Josee Verner, a former cabinet minister who lost her seat to her NDP challenger in the federal election earlier this month.

Harper said the trio will support his efforts to reform the Senate, including electing senators and putting an eight-year term limit on them.

"Our government will continue to push for a more democratic, accountable and effective Senate," he said in a news release.

But NDP Leader Jack Layton says Canadian voters just rejected these three people two weeks ago and Harper is making an anti-democratic partisan move.

"This is wrong. This is completely undemocratic. It's a slap in the face of Canadian voters," Layton said.

"Mr. Harper talks about Senate reform but he's doing things in the same old way, in fact, even worse ... The ink is barely dry on their rejection notices and they're being appointed to the Senate."

Layton said there is a "culture of entitlement" in politics that breeds cynicism in voters.

"You should earn your place in the Senate and, if you can't get elected, you shouldn't be appointed to the Senate two weeks later, that's for sure."

New Foreign Affairs Minister John Baird had no issues with defending the planned Senate appointments.

"Our party wants to see an elected Senate . . . and the only way we can do that is to have the elected government make appointments," he said on CTV's Power Play. "I think these three are outstanding Canadians . . . who are strongly supporting Senate reform."

NDP MP Pat Martin minced no words about the Senate appointments, saying "the Canadian public should be blowing their stack right about now."

"This is an insult to the democratic process . . . the Senate has become nothing more than a bullpen for washed-up political hacks and flacks and bagmen and now failed candidates."

Liberal Senator David Smith said Harper's move was "unusual, given what he was saying."

"But these are new colleagues we are talking about, I'm not going to attack them."

Duff Conacher of the advocacy-group Democracy Watch called for a police investigation into whether Smith and Manning were promised they'd get their Senate seats back if they lost in their bid for a seat in the House of Commons.

The Criminal Code says it's illegal to entice parliamentarians to resign for reward or profit, he said.

Smith, who resigned his seat in the Senate in order to run for a seat in Commons -- and lost -- will be returning to the Senate, over his own earlier objections to it.

On election night, after a disappointing third-place finish in his Montreal riding, Smith said he had "no illusion of returning to the Senate because I have resigned and that was a condition of me running."

"The condition for accepting the position in the Senate was I had to send my letter of resignation when I started campaigning," he told The Canadian Press in French on the night of the election.

"So I have no place there and I have no expectation of returning there."

Smith, a former CFL commissioner, was first named to the Senate in December.

Manning, who had been in the Senate since 2008 but stepped down to run for a seat in Newfoundland only to lose, will also be returning to his previous occupation.

Manning is a longtime Newfoundland politician.