Whether flying bombing missions over Europe for the Royal Canadian Air Force in the Second World War or exposing corrupt politics in Ottawa during his 30-year career as the Yukon's Progressive Conservative member of Parliament, Erik Nielsen was a fighter. And a successful one.

After first winning the territory's Conservative nomination in 1957, Nielsen defeated Liberal incumbent Aubrey Simmons in the federal election in June of that year. He never lost another election, holding his seat until resigning suddenly in 1987.

On Thursday, Nielsen lost the battle nobody can win, passing away after a massive heart attack suffered at his home in Kelowna, B.C. He was 84.

Former Liberal senator Ione Christensen was a one-time challenger of Nielsen, losing to him by 100 votes in the 1980 federal election, which brought Pierre Trudeau back to power.

She credits Nielsen - whom she called a Yukon icon - with getting her into federal politics. While the pair differed greatly in political philosophy, Christensen summed up Nielsen as tough but fair.

"It was a good campaign, based on principles and policies with very little negativity in it, so it was enjoyable to have a campaign like that," she said today. "I never belonged to any political party until I ran against him."

Flo Whyard, Whitehorse's mayor in the early 1980s and the editor of the Star in the 1960s, said Nielsen was a huge booster for the territory and a practical man with little time for pretension.

"He was an impatient man with a lot to do, but I had great respect for him," said Whyhard, who called Nielsen "Mr. Yukon" for the voice he gave the territory's residents in Ottawa.

After first being elected in 1957, Nielsen made the first federal proposal to allow the Yukon and N.W.T. a seat each in the Senate.

"He wasn't a backslapping kind of guy, a greeter, you know; he didn't have time for that; he was there to do the job and he did it," said Whyard.

"A lot of people thought he was cold, but you could understand why he was like that because he had been in the air force, and been through so much at such a young age."

As a pilot during the war, Nielsen flew 23 missions with a Lancaster bomber squadron, then as a commissioned pilot and officer another 33 missions, including the D-Day invasion and was awarded the Distinguished Flying Cross.

In politics, Nielsen became a confidant to prime minister John Diefenbaker. When the Diefenbaker government was defeated in 1963, Nielsen retained his seat and went on to expose Liberal corruption in Quebec and forced the resignation of then-justice Minister Guy Favreau.

Nielsen did so after he discovered that notorious Montreal drug dealer Lucien Rivard, who had escaped to the U.S., had been allowed to water a skating rink outside the confines of his Quebec prison cell in 1965.

This revelation resulted in another federal election in November of that year. Nielsen fought and won his sixth election in eight years, but it would not be until 1979 that Nielsen would be a member of the governing party.

However, serving under prime minister Joe Clark, that government would last a mere nine months. Nielsen would not taste power again until 1984, when the Conservatives, led by Brian Mulroney, were voted into office with 211 seats, the largest majority in government history.

Mulroney named Nielsen, his closest advisor, deputy prime minister. Nielsen also served for a time as Defence and Fisheries minister.

A two-week absence from Parliament by Mulroney forced Nielsen to defend fellow cabinet minister Sinclair Stevens, accused of using his ministerial powers for personal benefit. That would lead to his downfall.

Both Stevens and Nielsen ultimately resigned - a bitter pill to swallow for the loyal MP, who stepped down six months later, in 1987.

With his relationship with Mulroney in tatters, it is said his love for the House of Commons turned to disgust. That was evidenced by a book he wrote documenting his political career entitled This House is Not a Home.

Son Rick Nielsen said today his father was both pragmatic and disciplined.

"I would like to think, from my personal perspective, perhaps his legacy would be the work that he did for Yukon and Yukoners," he said.

"My father was very objective in his thinking and his undertakings and I think he maintained that discipline throughout his life ... and regardless of who you were or what you believed, you always knew where you stood with him."

Nielsen is survived by three children and his second wife, Shelley Coxford. Nielsen's first wife, Pamela June, died tragically of carbon monoxide poisoning in 1969.

Lawyer and longtime Conservative politician Don Cox remembers his colleague as a "very straight-up person" and astute politician who had no time for hypocrisy.

"He was a maverick," Cox told the Star. "He was very hard on his fellow members of Parliament.

"He was very critical if he thought they were doing something wrong. He had no time to talk about politicians (in terms of) other than what they were."

Cox said the campaign of presumptive Republican presidential nominee John McCain reminds him of Nielsen's own political style.

"They are both concerned about being straightforward and have no room for anyone to generate criticism that isn't well-founded.

"(Nielsen) was a good Progressive Conservative. He believed in the party's philosophy 100 per cent."

Cox said he first met Nielsen in the early 1960s, and used to campaign with him in Watson Lake when Nielsen was running campaigns. The two men also worked together as lawyers.

"I found him to be a very careful, studious but fair sort of lawyer when he worked for me and when he worked for others. He was a champion of first nations rights."

Outside of politics, Cox said, Nielsen was a good friend and a good person to know. Cox added that he and his wife held Nielsen in high regard for the many years they were acquainted.

The Nielsen family has not yet announced plans for a memorial service for the late MP.

Sarah Vanderwolf contributed to this story.