After years of acrimonious relations with the federal public service, outgoing Prime Minister Stephen Harper has issued a letter to Canada's "world-class public service" thanking members for their support and dedication to Canadians.

Harper, who was often at loggerheads with the public service over various policies and spending cutbacks, sent the "farewell message" to employees today thanking them for working closely with him and his team to improve the "prosperity, security and well-being of Canadians."

"I am very proud of the remarkable work we have accomplished together towards meeting these objectives," he wrote. "I would like to thank each and every one of you for the support you have shown my team and me over three successive Parliaments and for the dedication you have demonstrated in delivering for Canadians.

"It has been an honour to serve as prime minister of the greatest country in the world and I will always be grateful for the support of Canada's world-class public service."

Restore trust, respect: PSAC

The Public Service Alliance of Canada, the union that represents more than 170,000 federal employees across Canada, called it "unfortunate" that employees weren't recognized when the Conservatives were in office.

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"The work that public service workers do on behalf of Canadians day in and day out is invaluable. It is unfortunate that the Conservative government was not able to recognize the important contribution of public service workers during their mandate," said PSAC national president Robyn Benson in a statement to CBC News.

"We look forward to building a positive and constructive relationship with the new Liberal government where trust and respect for public service workers is restored."

During Harper's nearly decade in office, the Conservatives became embroiled in battles with the bureaucracy over spending and service cuts, policy decisions and restrictions on public commentary about research by federal scientists.

'Misleading' information

Harper reached out to federal employees during the election campaign, releasing an open letter to praise them for their accomplishments and attempt to clear up "misleading" information about contentious changes to the sick leave and pension programs. In that two-page letter, he used a conciliatory approach to explain the objectives of the changes.

Public Service Alliance of Canada national president Robyn Benson says it's 'unfortunate' employees weren't recognized while Conservatives were in office. (CBC)

But Harper took a much different tone in the final days of the campaign, repeatedly using a cash register machine stunt to warn what a new government would mean to taxpayers.

"We want this country to keep moving forward. We do not want to go back to the days where the government ran for a handful of Liberal special interest groups and the bureaucracy," Harper told a crowd at an event in Abbotsford, B.C., the day before the vote.