MONTREAL -- The race to replace Jean Charest as head of the Quebec Liberals is heating up, with two more candidates expected to enter the fray this week.

Philippe Couillard, a popular former health minister, has confirmed to The Canadian Press he will announce his candidacy on Wednesday.

Another Liberal, Pierre Moreau, is expected to enter the running on Monday.

Couillard is considered a possible frontrunner despite being out of politics for the past four years.

The 55-year-old former brain surgeon wants the Liberals to better defend Quebecers on key identity issues -- such as language and Quebec's place within Canada -- in order to compete with the newly-elected Parti Quebecois.

The province's former finance minister, Raymond Bachand, was the first candidate to officially enter the running last week.