(Recasts with environment minister replacement) By Randall Palmer OTTAWA, Jan 4 (Reuters) - Canadian Prime Minister Stephen Harper will replace his embattled environment minister, Rona Ambrose, on Thursday and is expected to shuffle other ministers as he tries to recover political ground he lost in the debate on climate change. The issue, suddenly a dominant one in Canadian politics, has put Harper's minority Conservative government on the defensive. When Ambrose arrived for a cabinet shuffle swearing-in ceremony on Thursday, a reporter asked her if she was getting a new job. She replied, "Yes -- very excited." It was not clear what her new portfolio would be, nor who would replace her in environment. The swearing-in ceremony will take place at 11 a.m. EST (1600 GMT), and Harper will make a statement 90 minutes later. Ambrose has faced mounting criticism over what are considered to be weak government plans to control greenhouse gas emissions, and for getting facts wrong. Canadians have shown an increasing concern for global warming, especially as they experience freakishly warm temperatures this winter. Harper, elected a year ago, is eager to shore up his team as he prepares for a possible election within months. He particularly needs to improve his standing in Quebec, which was key to the last election and which favors tougher action on climate change. Canadian media speculated that Treasury Board President John Baird could get the environment position. He is very quick on his feet in the daily Question Period in the House of Commons, especially in attacking the opposition parties, although some critics say his answers are over the top. Finance Minister Jim Flaherty, who travels this month to China for talks with Chinese officials, is expected to keep his job, as is Foreign Minister Peter MacKay. Others widely touted as part of the cabinet changes include Intergovernmental Affairs Minister Peter Van Loan and British Columbia Member of Parliament James Moore, who could get special responsibility for the Vancouver Olympics, which will be held in 2010. The Toronto Star also reported speculation that Wajid Khan, a Liberal member of Parliament, would cross the floor and sit with the government. Harper named Khan as a special adviser to him on the Middle East and Afghanistan last summer. That change would make it easier for the Conservatives to survive with the help of the left-leaning New Democratic Party, which propped up the previous Liberal government and has expressed an interest in working with the Conservatives. The Conservatives and the NDP would together have 154 of the 308 House seats, enough to stay in power since the Liberal speaker only votes to break ties. Minority governments in Canada traditionally only last about 18 months on average, and the government will face a key test when it delivers its budget, usually in February or March. Defeat of the budget would automatically trigger a new election. Opinion polls point to another divided Parliament, with neither of the two main parties likely to win enough seats to win a majority.
