For the Conservative Party, the addition of Belinda Stronach to their ranks a year and a half ago must have been seen as a coup.

The photogenic former executive was the perfect face for a party seeking to revamp its image into that of a moderate and strong alternative to the governing Liberals. The party hoped the well-heeled millionaire would bring some badly needed charisma and help woo younger, more moderate Conservatives.

It now appears that the traits that made Stronach such an attractive new politician -- her strongly held views and outspoken nature -- are what have now led her to turn her back on her adopted party and defect to the other side of the House.

Despite criticism from Conservatives who call Stronach's move a betrayal, she has the support of her friend and former prime minister Brian Mulroney.

"Brian said to me: 'Belinda, you're a friend. I support your decision as a friend,'" she said, appearing on CTV Newsnet's Countdown.

When asked whether the former Progressive Conservative was happy with her move, Stronach said: "I didn't ask him if he was happy or not. I very much appreciated that he called me and said, 'Look, I know how difficult this is and I support your decision.' I am very grateful for that."

Stronach, 39, entered politics in January 2004 as a challenger for leadership of the newly merged Conservative party, promising in her campaign to help the party get rid of the "tired, old Liberal government."

Indeed, in March 2004, Stronach criticized the leader.

"He would have you believe that he was a stowaway on the good ship Chretien when in fact he was the first mate," Stronach said of Martin, while condemning cuts to the military under the Liberal government.

While she came in a distant second to Stephen Harper, she managed to make an impressive debut and was able to secure her Ontario riding of Newmarket-Aurora in the 2004 election.

Stronach took the post of International Trade critic in Harper's shadow cabinet and has impressed many of her colleagues with her hard work and her determination to meet voters across the country.

She has also quickly learned the game of politics, surprising her fellow Tory MPs last Christmas by sending all of them flowers.

But she has never been shy about her ambitions, and has rankled some within her party by appearing to be openly campaigning to succeed Harper.

Others were not pleased when the twice-divorced Stronach publicly acknowledged a romantic relationship with Conservative House Leader Peter MacKay -- another Tory who once faced off against Harper for the party leadership.

"I have a great deal of respect for Peter MacKay ... and the contribution he's made to the growth of the Conservative party," Stronach said after announcing her defection.

Sources now say her defection comes as she and MacKay take a break from their relationship.

She would not comment on the future of their relationship. But that did not stop Harper from musing on the heartbreak of his fellow Conservative MP.

"If she has such a high opinion of Peter MacKay, I would venture today after my discussion with him, she has an awfully tough way of conveying that to him.

"I think Peter's taking this pretty hard, as you can imagine."

There have been other stirrings that Stronach was losing her ardour for the Conservatives.

Last month, she openly voted against her party by refusing to support a Conservative motion to derail Bill C-38, the same-sex marriage bill.

Then two weeks ago, Stronach let it be known that she was unhappy with Harper's decision to seek a spring election. She warned that aligning the Tories with the Bloc Quebecois would backfire and would eventually hurt Canada.

She also said that the billions promised for municipal infrastructure in the budget were extremely important to individuals in her riding north of Toronto, which includes many commuters who would benefit from improved roads, public transit and other transportation needs.

Unlike her western counterparts, Stronach has been wary of a quick return to the campaign trail.

She, like other Tory candidates in Ontario, was unsure they could win seats away from the Liberals.

It now also appears that she wasn't confident in Stephen Harper's leadership.

In her defection statement Tuesday, Stronach revealed that she didn't think Harper is "truly sensitive" to the needs and the complexities of Canada, adding she has been "uncomfortable for some time with the direction the leader of the Conservative Party has been taking."

Prime Minister Paul Martin calls Stronach's decision "gutsy"; Harper calls the move a betrayal.

As Stronach herself says, "Ultimately, the public will be the judge."

Stronach fast facts:

Age: 39; born May 5, 1966.

Family: Father is one-time Liberal candidate Frank Stronach, who founded multibillion-dollar Magna International auto parts; raised in Aurora, Ont.; twice divorced; two children from first marriage, to a Magna executive; second marriage to Norwegian Olympic speedskater; linked romantically to deputy Conservative leader Peter MacKay for the past few months.

Education: One year at York University in Toronto.

Private career: Former CEO of Magna International, the auto parts giant her father founded. National Post named her most powerful businesswoman in Canada in 2001; Fortune magazine ranked her No. 2 in its 2002 list of world's most powerful women in business.

Last private-sector salary: $12 million.

Base salary as an MP: $141,000.

Politics: Helped push Tory-Alliance merger, then ran second to Stephen Harper in March 2004 Conservative leadership contest; first elected to House of Commons in June 2004 federal election in sprawling well-to-do riding north of Toronto; appointed Tory international trade critic.

Riding: Newmarket-Aurora, Ont.

Policies: Supports lower taxes, leaner government; opposed to decriminalization of marijuana; supports gay marriage.

Languages: English, German.

Profile: Attracted attention of Time Magazine and U.S.-based Fox News in 2004 election campaign. Fox sought her out for personal meeting and hers was only riding Fox visited.

Quote: "I'm my own person; I make my own decisions.'' -- in an interview with The Canadian Press in 2004.