Prime Minister Stephen Harper will unveil his cabinet Wednesday, giving new jobs to at least six members of his majority government caucus, and naming John Baird to another key role.

CBC News has learned Baird will take over responsibility for the Department of Foreign Affairs and International Trade, which was left without a minister with the defeat of Lawrence Cannon on May 2.

Baird was most recently government House leader and has held important portfolios in the past, including Transport and Infrastructure.

Speculation about who is in, who is out — if anyone — and who else might be moved around, began soon after the Conservatives won the May 2 election and will come to an end Wednesday at 11:15 a.m., when the cabinet is sworn in at Rideau Hall, the Governor General's residence.

Governments like to keep cabinet appointments tightly kept secrets until just minutes before the ceremony is scheduled to begin. All eyes will be on who gets out of the cars once they arrive at the front doors of Rideau Hall. The entire cabinet is expected to attend Wednesday's ceremony.

Live coverage Wednesday

CBC will have live coverage of the cabinet swearing-in ceremony Wednesday morning at CBCnews.ca and with Power & Politics host Evan Solomon starting at 10:30 a.m. ET on CBC News Network.

With six spots to fill, including three on the government's front bench, this will be one of the most major cabinet shuffles in years. The last time Harper made changes, this past January, he made only minor tweaks.

The vacancies need to be filled because of ministers who retired or lost in the May 2 election.

The gaps that need to be filled include the heavyweight portfolios of Foreign Affairs, president of the Treasury Board, and Transport and Infrastructure, and the smaller ones of intergovernmental affairs, veterans affairs and sport.

Harper has to take geographic representation into account when deciding who gets to sit at the cabinet table, and this is where he faces particular challenges.

The retirement of Chuck Strahl and Stockwell Day leaves two spots open from British Columbia, which could mean a promotion for James Moore, the current heritage minister, and the inclusion of more MPs from that province.

Few Quebec MPs

Harper has also lost three cabinet members from Quebec with the defeat of Cannon, Jean-Pierre Blackburn and Josée Verner on election night. He now only has five MPs to choose from in Quebec and two of them are already in cabinet — Denis Lebel and Christian Paradis. Harper may decide to bring Maxime Bernier back into the inner circle to help boost Quebec's representation. The former foreign affairs minister resigned in 2008 after leaving confidential documents at his girlfriend's residence.

While pickings are slim in Quebec, there is no shortage of cabinet candidates from Alberta and Ontario. The Tories hold all but one of Alberta's 28 seats and the MPs already in cabinet from that province — Jason Kenney, Rona Ambrose, Ted Menzies, Rob Merrifield, and Diane Ablonczy — probably aren't going anywhere.

The Conservatives may bulk up Ontario's contingent in cabinet now that they finally broke through the Liberal fortress in Toronto and have a number of capable rookie MPs joining the caucus from the city and its suburbs. Chris Alexander and Kellie Leitch are both new MPs with cabinet speculation surrounding them.

Industry Minister Tony Clement, Finance Minister Jim Flaherty and Baird, all from Ontario, have been steady and trusted ministers in Harper's cabinet.

In addition to geographic representation, Harper also has to be attuned to how many women he includes in his cabinet. The old one had 10 which includes Senator Marjory LeBreton who is leader of the government in the Senate. Eight out of the other nine were re-elected.

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