Former finance minister Jim Flaherty has died at the age 64, nearly a month after he stepped down from cabinet ahead of a planned move to the private sector.

The cause of death was not immediately available, but it’s believed that Flaherty suffered a heart attack. Paramedics were called to his Ottawa condominium shortly after noon Thursday, and he was pronounced dead not long after, police said.

Flaherty’s wife, Ontario Progressive Conservative MPP Christine Elliott, and the couple’s triplet sons, John, Galen and Quinn, issued a brief statement asking for privacy. The statement said Flaherty “passed away peacefully.”

“We appreciate that he was so well supported in his public life by Canadians from coast to coast to coast and by his international colleagues,” the family statement read.

The House of Commons was suspended after the news of Flaherty’s death broke Thursday afternoon. The Ontario legislature was also adjourned for the day.

The flag on the Peace Tower at Parliament Hill was lowered to half-mast.

Prime Minister Stephen Harper said “today is a very sad day for me, for our government and for all of our country.”

“Jim will be sorely missed, not only by his many friends on both side of the House, I know particularly his friends in this caucus, among whom he was held unanimously in a combination of great respect and affection,” Harper said in a statement to the Conservative caucus.

“But he will also be missed by the countless thousands of Canadians that he devoted himself to and whom he helped during his long and successful career in public life.”

Harper said that he will speak more about Flaherty’s legacy and “the special relationship I shared with Jim” in the days ahead. Harper appeared with his wife Laureen, who was wiping tears from her eyes.

Former and current MPs and MPPs of all political stripes paid tribute to Canada’s longest-serving finance minister.

Joe Oliver, who succeeded Flaherty in the finance post, said he was “shocked and very saddened” to learn of Flaherty’s death.

“He was an honourable, dedicated and exceptional man who loved Canada,” Oliver said.

NDP Leader Thomas Mulcair said he and his wife, Catherine, “are very, very sad at the loss of a great Canadian.”

Mulcair, near tears, made a brief statement outside the House of Commons. He paid tribute to Flaherty, calling him an “extraordinarily dedicated public servant.”

Liberal Leader Justin Trudeau issued a statement, saying he learned of Flaherty's death "with great shock and sadness."

"Jim was a dedicated Parliamentarian with a strong social conscience and fundamentally committed to the ideal of public service," Trudeau said. "He was a proud Canadian and showed continued devotion and commitment to his country over many years. This is a loss to the entire family in the House of Commons."

Green Party Leader Elizabeth May issued a statement offering her “deepest condolences” to Flaherty’s family.

“He was a rare partisan, able to extend a mischievous twinkle to a rejoinder in Question Period,” May said. “He was a dedicated public servant and a genuinely kind man. He will be missed.”

Other MPs took to Twitter to express their shock and sadness.

“Deeply saddened to hear that Jim Flaherty has died – he was a tenacious, effective and dedicated politician who reached across the aisle,” tweeted former Liberal leader Bob Rae.

NDP MP and finance critic Peggy Nash tweeted: “Oh so sorry to learn news about Jim Flaherty. Very very sad.”

Former Bank of Canada Governor Mark Carney issued a statement saying Flaherty “has exhibited the very best of Canadian virtues in service to our country.”

“He was a man of principle who believed in fixing banks when they were broken, sound money and balanced budgets,” said Carney, who is now the Governor of the Bank of England.

While he butted heads with Flaherty during his five years as Canada's parliamentary budget officer, Kevin Page described the former finance minister as "a formidable person to have to go up against."

"There was always a respect," Page told CTV News Channel. "I knew I was dealing with a minister of finance that was giving 24-7 attention to the country's finances."

Page said he believes Flaherty's greatest success as finance minister was his ability to put Canada on track to a balanced budget in 2015.

"I think people will look back and thank Mr. Flaherty for the strong books."

G20 finance ministers and central bank governors who are currently meeting in Washington issued a statement Thursday evening mourning Flaherty’s death.

“Jim was a man of strong principles and held firm to his core values,” said the statement from Australian MP and Treasurer Joe Hockey.

“As one of Canada’s longest serving Finance Ministers, he made an enduring and significant contribution to Canadian public policy and to the wellbeing of the Canadian people.”

Former prime minister Brian Mulroney said Flaherty’s leadership during the 2008 global recession “saved our bacon” and earned him respect around the world.

Mulroney told CTV’s Power Play that although the prime minister always calls the shots, Harper had “enormous” respect for Flaherty and his opinions throughout the years that they worked together.

Flaherty stepped down from his post as finance minister last month, citing plans to eventually take a job in the private sector. At the time, Flaherty said he and his family came to the decision that he would resign from cabinet, but did not say whether he would remain an MP until the 2015 election.

He denied that his health had anything to do with the move.

He had been coping with a painful skin condition, Bullous Pemphigoid. The condition required him to take powerful medications that left him appearing bloated, and looking and sounding at times extremely fatigued.

In a statement announcing his resignation from cabinet, Flaherty said that he was “on the road to a full recovery.”

Flaherty was born in Lachine, Que. on Dec. 30, 1949 and, after growing up in Quebec, went on to earn a BA from Princeton University and a law degree from York University’s Osgoode Hall Law School.

He helped found law firm Flaherty Dow Elliott before jumping into provincial politics in the early 1990s.

He lost his first time out, but won the Whitby-Ajax riding in 1995 and held several cabinet posts over the next decade, including labour, finance and deputy premier.

After two unsuccessful attempts to win the leadership of the Ontario Conservatives, he made a successful leap to the federal scene in 2006, winning in Whitby-Oshawa.

As federal finance minister, Flaherty made tax cuts a priority, starting with a one-per-cent cut to the GST, followed by another cut in 2008.

In 2007, Flaherty introduced the Registered Disability Savings Plan to help Canadians with disabilities save for retirement, and in 2008 introduced the Tax-Free Savings Account.

He also raised the base deduction rate, cut a point from the lowest personal tax rate and raised the limits of the two lowest tax categories.

Flaherty wasn’t afraid to spend, however, once the 2009 recession hit, pouring billions of stimulus into the economy via the Economic Action Plan.

When he stepped down last month, Flaherty thanked his constituents, his House colleagues, his wife, who represents her husband’s former provincial riding, and their sons.

“We live in the greatest country in the world, and I want Canadians to know that it has been my honour and my privilege to serve them,” Flaherty said.