A volunteer group that tends to one of Halifax's national historic sites says Parks Canada it trying to drive them out.

Parks Canada has cancelled its $1,500 annual volunteer agreement with Friends of McNabs Island Society, which has cleaned up the fort on McNabs Island for the past 17 years.

Over the years the volunteer group has used the money to clean up garbage, look after the cemetery and provide general cleanup work to the fort, which played a key role in protecting the city during both world wars.

"It is a national historic site, it is as important as the Halifax Citadel," said Catherine McCarthy, the society's president.

Parks Canada said its staff will assume responsibility of the fort after it spent close to $1.6 million to improve the site in the spring.

McNabs Island in Halifax harbour played a key role during both world wars. (CBC)

In an email to the society, Parks Canada cites government cuts and said maintenance will be done by Parks Canada at minimal cost. It told the society their services are no longer needed.

"We did offer to do it for free we said we'd try and find a sponsor to pay for our costs, our transportation and insurance costs, but they weren't interested," said McCarthy.

MP Peter Stoffer said he plans to ask the government to reverse the decision.

"Dollar for dollar, they are much more fiscally responsible in terms of maintaining that island and looking after it and these people love the island. Anyone who has been there knows it's a jewel," he said.

Stoffer called the move "shameful."

Parks Canada was one of the hardest-hit departments in federal budget cuts, with 1,689 affected notices going to the agency that runs national historic sites and national parks.

McCarthy said the Friends of McNabs Island Society will still be doing cleanups of the island.

Since 1991, their volunteers have collected more than 10,670 bags of garbage and recyclables from the shorelines of McNabs, Lawlor Islands Provincial Park and the Fort McNab National Historic Site.