Stephen Harper has been elected leader of the Canadian Alliance Party, winning a convincing first-ballot victory.

The party announced the results of the mail-in leadership vote in Calgary on Wednesday night. Harper won with 55 per cent of the vote, surprising many who had predicted a second ballot would be needed.

"You have just voted to move our party forward into the future," Harper told the crowd gathered to hear the results.

"We will continue to be guided by the founding principles of this party," he said. "We must be the party that believes taxpayers are as important as politicians, that ranks and file workers are as important as union bosses."

For much of the campaign Harper and Stockwell Day were considered the front-runners, far ahead of Diane Ablonczy and Grant Hill. But many observers expected none would win a clear majority.

Harper, 42, is a former MP with the Reform Party. Since leaving Parliament in 1997, he has led the National Citizens' Coalition, a right-wing lobby group.

He was a founding member of the Reform Party, and was involved in drafting early Reform policy. He decided not to seek re-election in 1997 after a falling out with Reform founder Preston Manning.

All party members who signed up before March 1 were eligible to vote by mailing in ballots between March 8 and March 15. There were 124,000 ballots issued, and 88,228 were returned.

Day urged the party to rally around the new leader.

"We are so glad there's a conclusive result here tonight," he said. "Second ballot races are no fun."

A second mail-in ballot would have been held over the next week if no one had candidates had received a clear majority of the votes, with those results announced at the party convention April 4.

Hill said Harper's election offers the party a chance to move beyond the troubles that forced Day to step down.

"He has a lot of caucus support," Hill said.

"It looks like the membership has chosen internal rebuilding ahead of external co-operation."

Harper said during the campaign he wasn't interested in discussing uniting with the Progressive Conservatives as long as Joe Clark leads the Tories.

The leadership vote was precipitated by a caucus revolt over Day's leadership of the party. He stepped down after 13 caucus members walked out to protest his poor performance both in the 2000 election and in the House afterward.

Six of the defecting MPs eventually returned to the Alliance fold, but the remaining seven decided they couldn't stay under Day's leadership and they formed a coalition with the Tories.

Harper said he would welcome the dissident MPs back.

"I feel they should be back," he told CBC News. "My view is they have a moral obligation to serve as Canadian Alliance MPs...

"The door is open."

Ablonczy said she hoped the dissidents, who include party stalwarts Chuck Strahl and Deb Grey, would come back.

"Canadians want to see us turning a corner and healing our rifts," Ablonczy said.

Harper has to win a seat in the House of Commons before he can take on the role as leader of the Opposition, which he said he would rather do sooner than later.