Alberta Premier Jim Prentice and former Wildrose Leader Danielle Smith speak to media after a caucus meeting in Edmonton Alta., Wednesday, December 17, 2014. Prentice's caucus met to discuss a bid by at least half the official Opposition to cross the floor. THE CANADIAN PRESS/Jason Franson

EDMONTON - The leader of Alberta's Official Opposition shattered her caucus Wednesday by leading an en masse floor crossing, saying she no longer had the fire in the belly to oppose Premier Jim Prentice.

"If you're going to be the official Opposition leader, you have to really want to take down the government and really want to take down the premier," Danielle Smith, standing beside Prentice, told reporters at a news conference at Government House.

"I don't want to take down this premier.

"I want this premier to succeed, and I want to be part and parcel of helping him succeed."

Earlier Wednesday, Smith and eight of her Wildrose party colleagues were accepted into Prentice's Progressive Conservative caucus, leaving behind a five-member rump while elevating the Tory majority to an overwhelming 72 seats in the 87-seat legislature.

NDP and Liberal leaders accused Smith of an unprecedented betrayal of Wildrose supporters and voters along with those Albertans who rely on a strong opposition to keep a government in check.

But Smith said there was no longer any need to oppose a premier who, unlike his predecessors, agreed with what the Wildrose believed on issues such as land rights and fiscal conservatism.

"We won," said Smith.

"We clearly managed to move away from two administrations that were not moving Alberta forward, that were not serving Albertans well, and we have a premier that shares the same conservative values that we do."

Smith said she has asked the party and caucus to consider folding up shop to join the PCs in a provincial unification of the centre-right.

"I'm asking Wildrose members to come with us," she said.

The Wildrose executive has already denounced the floor-crossings and in an email said it plans to fight on to contest the next election, slated for 2016.

"We have begun the process to select the next leader of our party and the next premier of Alberta," said the email. "We remain fully committed to Albertans and to our membership."

Smith said there had been informal talks between intermediaries for months on joining forces with Prentice, adding that interest in a union accelerated in recent weeks.

Prentice said the decision by his caucus to accept the Wildrosers was not unanimous but said "the support was overwhelming."

He said it was a good day for those working to make Alberta better, and said there are no immediate plans to shake up his cabinet to make room for Smith or her MLAs.

Prentice saluted Smith.

"Danielle, you've shown considerable personal courage and determination in making this decision," he said. "This is the same courage and determination that has served you and your team so well during your five years as leader of Wildrose."

Joining Smith in the defection was her key lieutenant, government house leader Rob Anderson.

Anderson was elected as a Tory in 2008 but crossed the floor to the Wildrose in 2010. He was elected as a Wildroser in 2012 before crossing back to the Tories on Wednesday.

In an open letter, Anderson said it was better to now work inside the tent than engage in histrionic attacks from the outside.

"Why do we elect MLAs? To put on a partisan jersey and fight partisan battles for some kind of entertainment? I sure don't think so," wrote Anderson.

The other seven joining the PCs are: Gary Bikman, Jeff Wilson, Blake Pedersen, Bruce McAllister, Jason Hale, Rod Fox and Bruce Rowe.

They join former caucus mates Ian Donovan and Kerry Towle, who quit the Wildrose last month, saying they were impressed with Prentice and his team.

The opposition now consists of five leaderless Wildrosers, five Liberals, four NDPers and Independent Joe Anglin.

Anglin quit the Wildrose in November.

Liberal Leader Raj Sherman said he will ask the Speaker to install the Liberals as the new official opposition.

"The PCs and the Wildrose are one and the same," said Sherman.

"The Liberals are the only sensible, centrist alternative right now in Alberta."

NDP Leader Rachel Notley labelled the floor-crossings a "betrayal" of Albertans by a premier whose party was elected on a progressive platform in 2012 but who she said is now cynically tacking hard right to vacuum up its main political opponent.

"Jim Prentice may think, 'Oh look at me, look at how Machiavellian and clever I am,'" said Notley. "But I think that it will really offend the basic values of many Albertans."

The move brings into doubt the future of what had been considered the most effective official Opposition in Alberta in years.

The Wildrose was borne out of disgruntled Tories who quit the party as it moved left toward bigger budgets and budget deficits under former premier Ed Stelmach.

The polls had Smith and the Wildrose leading at one point in the last election campaign only to see its credibility unravel in the closing days by racist and homophobic statements from two of its candidates.

The Wildrose has since helped to expose spending and entitlement scandals that led to the resignation in March of then-premier Alison Redford.

In September, Prentice replaced Redford and on Oct. 27 the Tories defeated the Wildrose in four byelections, renewing concerns about the Wildrose prospects to form government while raising questions about Smith's leadership.

News from © The Canadian Press, 2014