Canadian foreign minister John Baird will be announcing his resignation from the Cabinet today.
A senior government official who is close to the minister said Mr Baird felt it was the right time to move on after a successful career in Ontario provincial politics and the national parliament.
The 45-year-old is one of Conservative prime minister Stephen Harper's most trusted and loyal cabinet ministers, and previously served in his cabinet as house leader, environment minister, transport minister and treasury board president.
Mr Baird has a reputation for being hyper-partisan, and he often escorted Mr Harper's wife, Laureen, to official events when the prime minister could not attend.
A statement from Mr Baird's office said he planned to make an announcement in parliament this morning, but did not disclose any details.
The senior government official said Mr Baird will not be running for parliament in the next election, scheduled for October.
"The minister is looking to turn the page on 20 years of public service, and like anyone in public office is looking for new opportunities at the young age of 45," the official said.
Mr Baird has also served as a minister in Ontario's provincial government.
He had little international experience before becoming foreign minister in 2011. He was known as a staunch supporter of Israel.