Longtime Nova Scotia MP Scott Brison says he won't run for re-election this year and is stepping down from cabinet, triggering a shuffle early next week.

Brison, who sits at the cabinet table as president of the Treasury Board of Canada, made the announcement online Thursday morning.

His departure leaves a vacancy at the cabinet table and the Prime Minister's Office says changes will be announced on Monday.

Prime Minister Justin Trudeau was asked about the shuffle during a stop in Kamloops Thursday, but wouldn't say whether he's looking at simply replacing Brison or planning a larger shuffle with multiple ministers switching chairs.

"Obviously this will require some changes to our cabinet, and that's something that we're going to be announcing on Monday," ​he said.

I would like to share an important family decision: I’ve informed the Prime Minister of my decision to not seek re-election in 2019. As such, I’ve decided to step down from my role as President of the Treasury Board and will work with the PM to ensure a smooth transition. <a href="https://t.co/JdsZTSH2HI">pic.twitter.com/JdsZTSH2HI</a> —@scottbrison

Whoever takes over the job as Treasury Board president will be accountable for the government's fiscal operations and overseeing the federal public service.

Brison spent 22 years in politics and made history as the first openly gay federal cabinet minister.

The father of twins said he's looking forward to spending more time with his husband and children.

Prime Minister Justin Trudeau reflects on Scott Brison's contribution to his cabinet. 1:49

"It's time to put my family first and to think of new opportunities. Life begins at 50, I'm 51 and I'm very excited about opportunities to do something different while continuing to help and serve people of Canada and the people of Kings-Hants in a different way," he told CBC News.

"Absolutely, I'll miss politics. I believe politics matters. I believe government matters."

Brison first won the Kings-Hants seat in 1997 as a Progressive Conservative before crossing the floor in 2003, and has held cabinet portfolios in the Liberal governments of Paul Martin and Justin Trudeau. (He did briefly step aside as an MP so Progressive Conservative leader Joe Clark could return to the House of Commons as part of his political comeback.)

"You've stuck with me through thick and thin, the good times and the tough ones. What a trip we've had together," he wrote in an open letter to constituents.

"Two political parties. Seven elections. You stood with me in December 2002, when I came out … and in December 2003, when I came out again — this time as a Liberal."

Brison fought for same-sex marriage during his Progressive Conservative leadership bid and the 2004 election — and even sparred publicly with fellow MP Elsie Wayne over the issue.

Brison, right, and his husband, Maxime St-Pierre, married in 2007 and have twin daughters Rose and Claire. (Twitter)

He was part of the cabinet that brought in same-sex marriage legislation. He and his partner, Maxime St. Pierre, married in 2007, making Brison the first MP to wed his same-sex partner.

In an interview with CBC from his home in Cheverie, Brison said he's proud of the role LGBT rights play in his political legacy.

"I hope that in some way, my simply living my life openly has helped make a difference in the lives of people and taking down some of the barriers that have existed," he said.

"In some ways I've had the unique privilege of helping be part of, as government, of helping shape social progress that has benefited Canadians, but also which has impacted in a profoundly positive way my own life as a Canadian. There's not too many people that have that opportunity and I think I've been truly blessed."

Role in Norman case questioned

In recent months, Brison has had to dodge questions about his role in the Vice-Admiral Mark Norman affair.



Norman is accused of leaking cabinet secrets to executives at the Davie shipyard, in Levis, Que., in the run-up to the signing of a $668 million lease contract for a temporary navy supply ship.

Brison has been hammered in the House of Commons with questions about whether he was in contact with Irving Shipbuilding of Halifax prior to a key cabinet committee meeting at the heart of the criminal case against the former commander of the navy.

For 22 years he's been a tireless champion for the people of Nova Scotia and for Canada. And one of the friendliest people you will ever meet in this business. <a href="https://twitter.com/scottbrison?ref_src=twsrc%5Etfw">@ScottBrison</a> - our country is better for your service and dedication. Our immense thanks to you, Max & the girls. <a href="https://t.co/lEPqbwTLd7">pic.twitter.com/lEPqbwTLd7</a> —@JustinTrudeau

He's maintained his only engagement with Irving Shipbuilding during the period in question was being copied on a letter the company sent to four cabinet ministers extolling the virtues of their proposal.

Brison also told the House of Commons that his objection to the project related only to his job as Treasury Board president.

Brison, along with Environment Minister Catherine McKenna and former Conservative defence minister Peter MacKay, are all on the Crown's witness list and could be called to testify.

The trial will not get underway until August — just before the next federal election campaign kicks off.

Best wishes and congrats to NS MP <a href="https://twitter.com/scottbrison?ref_src=twsrc%5Etfw">@scottbrison</a> who represented our Prov of NS for more than 20 yrs. More family time with your young girls @ home is a genuine calling. —@PeterMacKay

In an interview with The Canadian Press, Brison denied that his decision to quit politics is in any way related to the Norman controversy.

"If that issue had never occurred, I would be making the same decision that I'm making now," he said.

Brison told CP he's announcing his decision now to give his riding enough time to organize a nomination race.

The former investment banker said hasn't taken a new job yet.

Treasury Board President Scott Brison joined Power & Politics Thursday to discuss his decision to leave politics and what he plans on doing next. 8:10

"My personal view is that the prime minister and the government are best served by ministers who will be running in the next election," he said.

Trudeau rushed to Twitter to praise Brison, describing him "a tireless champion for the people of Nova Scotia and for Canada" and as "one of the friendliest people you will ever meet in this business."

MacKay, who was elected in the same year as Brison and beat him in the 2003 leadership convention, tweeted "best wishes and congrats" to his former caucus colleague and said that spending more time with family is "a genuine calling."