More than 100 former Parks Canada employees have signed an open letter saying they have concerns about the firing of a senior parks scientist in Jasper, Alta., this summer.

They also criticize what they call the "purging of science-based management" in national parks, and are blaming the federal government.

The letter appeals to Canada's opposition parties during the election campaign. 

Former parks staff with careers ranging from biology to administration to heritage are among those who signed the letter.

Among the signatories is Nik Lopoukhine, the former director general of national parks, who raised concern about the firing of John Wilmshurst, a former resource conservation manager at Jasper National Park. The letter does not state why Wilmshurst was fired last June.

"We're just pointing out that this man was a top scientist recognized not only internally but externally," he told CBC News.

Scientist has no comment

Wilmshurst has declined to comment, and Parks Canada said his employment situation is a human resources matter and the agency does not comment on issues of this nature.

"Fundamentally the issue is who is providing scientific advice in regards to decisions such as Lake Louise and other developments," said Lopoukhine. 

Rick Searle, a former Parks Canada naturalist, also signed the letter.

He said he would like to see the issues raised be part of the discussion for federal candidates. 

"What are they prepared to do to restore science capacity within the national parks, and national historic sites as well?" Searle said.