The Canadian public servant who fell foul of his bosses when his protest song about the nation's government went viral on YouTube, has walked away from his job.

Singer-songwriter Tony Turner, who was also a geographer with Environment Canada, was suspended and under investigation for allegedly breaching the bureaucracy's ethical code.

The case sparked a national debate about freedom of speech and the right of public servants to take part in political activities.

It mirrors similar cases in Australia in recent years but, unlike Australians, Canadians' freedom of expression is protected by their constitution.

Turner, well known in the Canadian capital Ottawa's folk music scene, recorded the protest song Harperman in June with an impromptu choir calling themselves the Crowd of Well Wishers.

The tune has been viewed almost 700,000 times on YouTube but was not a hit with Environment Canada, which placed its employee on suspension pending a full investigation.

But Mr Turner brought the process to and end, retiring from his job, effective Friday.

"When Environment Canada suspended me earlier this summer, I was assured a quick investigation and decision," he told the Ottawa Citizen.

"That has not happened, and I have decided it better to retire and continue to express my views as all Canadian citizens are entitled to do."

But he is adamant that he was within his democratic rights to write and perform his song, although he conceded he might have been more "circumspect" about its posting on the video sharing site.

"I did my job objectively, impartially and I did it well," he said.

"I felt that anything I did outside of the context of my work was allowed to be done under the charter of rights and freedoms.

"I have no regrets about writing the song."

Like the APS code of conduct, the Canadian government's values and ethics code says staff must carry out their work "in a non-partisan and impartial manner".

A former head of the Ontario provincial public service, Tony Dean, told The Globe and Mail in September that Turner's song "well and truly" violated the bureaucracy's apolitical nature, particularly given the looming election.

However, the president of the Professional Institute of the Public Service of Canada, Debi Daviau, told the Ottawa Citizen that Turner's expression of his political opinions did not interfere with his ability to perform his research, which was most recently on migratory birds.

She said the "rights of Canadians shouldn't be different between the private and public sectors. The right to participate in the federal election is the same and so is the right to free speech."

Most APS agencies warned Australian public servants of the risk of making political comments in 2013, in the wake of the Immigration Department's decision to sack Michaela Banerji.

Ms Banerji had used an anonymous Twitter account to criticise the government's refugee policies.