CTV has learned that Foreign Minister Peter MacKay was not told by his party or his leader that the Prime Minister was going to stand up in the House of Commons and challenge the Atlantic premiers to take the feds to court on the Atlantic Accord.

Robert Fife has more on the CTV video sidebar.

CTV News has learned a weekend letter on the Atlantic Accord dispute has left Prime Minister Stephen Harper facing a major cabinet split.

Sources say that Foreign Affairs Minister Peter MacKay feels blindsided by the letter to the editor published Saturday that inflamed matters.

Insiders say that Sandra Buckler, the prime minister’s communications director, instructed MacKay to sign the letter, which rejected any side deals with Nova Scotia.

MacKay, a Nova Scotia MP and the senior minister for Atlantic Canada, refused, say sources. Finance Minister Jim Flaherty signed the letter.

Nova Scotia pulled out of talks with the federal government in response. Conservative Premier Rodney MacDonald called on Atlantic MPs to vote against the federal budget.