Former immigration minister Chris Alexander is expected to join the race for the federal Conservative leadership.

A source with close knowledge of the race confirms Alexander is gathering the necessary signatures and financial support and building a team for a run.

The source says his campaign is expected to focus on foreign policy and the economy.

The 48-year-old former ambassador to Afghanistan was seen as a rising star when he ran for the Conservatives in the Toronto-area riding of Ajax-Pickering in 2011.

Two years later, Stephen Harper brought him into the cabinet as immigration minister.

But Alexander became embroiled in controversy during last year's election campaign amid questions about the government's handling of the Syrian refugee crisis.

He was also criticized for promising, along with then-labour minister Kellie Leitch, to create a telephone tip line to report so-called "barbaric cultural practices."

Leitch is also running for the leadership and has again stirred up controversy for promising to devise a "Canadian values" test for immigrants.

Blaney resigns as critic

On Friday, another former cabinet minister, Steven Blaney, issued a press release saying he was stepping down as the opposition critic for public services and procurement.

Conservative MP Steven Blaney is stepping down from interim leader Rona Ambrose's team of opposition critics, a move he calls a "new step" towards a possible leadership bid. (Sean Kilpatrick/Canadian Press)

The Quebec MP's statement said his decision "represents a new step toward his reflection about the future of the Conservative Party."

On Thursday, Michael Chong became the first candidate to pay the full $100,000 registration fee required in the race to replace Harper, who stepped down after the Conservative election loss last fall.

The contenders, so far

Candidate who has declared, registered and paid the full fee: Michael Chong.

Candidates who have declared and registered: Maxime Bernier; Tony Clement; Kellie Leitch; Deepak Obhrai.

Potential candidates who have declared only: Dan Lindsay; Pierre Lemieux; Adrienne Snow; Brad Trost.

Expected to declare soon: Chris Alexander; Steven Blaney; Andrew Scheer.

Others who have mused about running but not declared: Kevin O'Leary; Erin O'Toole; Rick Peterson; Lisa Raitt.