Voters in southwest Calgary will cast their ballots Monday to choose a new MLA in a byelection.

The Calgary-Glenmore riding has been held by the governing Progressive Conservatives since the late 1960s.

A byelection was called when former deputy premier Ron Stevens resigned prior to his appointment as an Alberta Court of Queen's Bench judge.

The Tory candidate, former Calgary alderman Diane Colley-Urquhart, has boasted of her deep Conservative roots. She is president of Prime Minister Stephen Harper's Calgary-Southwest constituency association and also worked for Stevens as a volunteer.

The Opposition Alberta Liberals chose psychiatrist Avalon Roberts to represent them.

Roberts, who challenged Stevens in the last two provincial elections, has served as the president of the Alberta Psychiatric Association and as provincial chairwoman for the Friends of Medicare.

Keith Brownsey, a political scientist at Mount Royal University in Calgary, said the riding will probably stay Tory blue, but bubbling discontent over the Alberta government's handling of the economic crisis could lead to an upset.

Brownsey said that although the seat has remained Tory for some time, it is not a stronghold. Some of the past margins of victory over Liberal challengers have been fairly slim.

He also pointed out that there is some discontent in Calgary with Alberta's rapid fall from boom to bust, but it's not clear whether that will translate to changes at the ballot box.

"I don't think there's much there to indicate that the Conservatives will lose."

Tories' huge majority not threatened

Paul Hinman, former leader of the Wildrose Alliance, represents his party.

Social Credit Leader Len Skowronski is also running in the byelection, while Eric Carpendale, a journeyman electrician and Habitat for Humanity volunteer, represents the NDP.

In the 2008 provincial election, Stevens took 51 per cent of the vote and Roberts took 33 per cent.

Alberta Premier Ed Stelmach has visited Calgary several times in the last month to attend rallies with Colley-Urquhart. He wouldn't speculate last week on what it would mean if the party lost the seat.

"If she loses, we'll look at the results of the election and see what the message is," Stelmach said.

In the end, Brownsey said, a loss for the Tories would be a temporary blow and would mean very little in the long run given the government's overwhelming majority.

Stevens's departure left the Conservatives with 71 of Alberta's 83 seats. The Liberals have nine members and the New Democrats two.