The race for the leadership of Alberta's Progressive Conservatives is going to a second ballot, the CBC has learned.

None of the six candidates managed to scoop the 50 per cent plus one ballots required for a decision in Saturday's vote. A second ballot featuring the top three finishers — Gary Mar, Alison Redford and Doug Horner — will be held in two weeks.

The winner will succeed Ed Stelmach as party leader and premier of Alberta.

Ex-finance minister Ted Morton, Rick Orman and backbencher Doug Griffiths have been eliminated.

The six candidates have been campaigning for months to replace Premier Ed Stelmach, who announced in January he was leaving politics.

Observers and polls suggested that Mar was the front runner from the start, but the popular belief was that he didn't have enough support to avoid a second ballot.

The campaign started immediately after Stelmach made a surprise announcement in late January that he was stepping down. Two days later, Morton resigned his position as finance minister to run for the party's top job.

Redford, the justice minister, and Horner, the deputy premier and advanced education minister, joined the race shortly afterwards. Like Morton, they resigned their cabinet posts, following guidelines put in place earlier by Stelmach.

Griffiths, a junior cabinet minister and MLA for Battle River-Wainwright, declared his intentions in mid-February.

Mar, a former cabinet minister under Ralph Klein, resigned his post in March as the province's envoy in Washington, D.C., to enter the race. Rick Orman, a member of ex-premier Don Getty's cabinet, was the last to join the race in May.

Duane Bratt, a political scientist at Mount Royal University in Calgary, says it's been a tame campaign so far, but he believes the race will change over the next two weeks.

Mar seen as front-runner

"By and large, the only person that they've been bashing has been Ed Stelmach," he said. "Come the second ballot, though, I think that's when you're going to start to see more going after each other."

Mar was identified as the front-runner in a controversial poll released this week by the Calgary Herald newspaper.

The Environics poll found their polling subjects using a party membership list that candidates say was supposed to be confidential.

On Thursday, Orman called on the party to investigate. He questions the accuracy of the poll because he doesn't believe enough of his supporters were surveyed. He also objected to the results being released the day advance polls opened.

"I've asked my fellow candidates to support me by signing a letter to the party and agreeing to an investigation, agreeing to the fact that we should investigate this matter," Orman said. "I believe the party should request the poll back from the Calgary Herald or from Environics."

The race has also seen its share of other controversies. There were allegations Mar's campaign broke party rules by allowing his supporters to sell memberships within 50 metres of the advance polling stations.

A CBC News investigation revealed that Morton used a second email account under his real name "Frederick Lee" for government communications when he was a cabinet minister and shredded documents after he resigned from cabinet.

Morton denied he did anything wrong and said many provincial and federal cabinet ministers have secondary email accounts.