OTTAWA — They are the people who seem to have found themselves on Prime Minister Stephen Harper's political black list: A nuclear regulator, a watchdog of the RCMP, an ombudsmen for victims of crime, a champion for military veterans. And now — say Harper's critics — a senior Mountie who had the temerity to defend the long-gun registry.

Their supposed political crime? To argue their case too forcefully, or to adopt a position frowned upon by the Harper government. Their punishment? In some cases, a pink slip. In others, banishment. This is the reputation — rightly or wrongly — that Harper is earning for his government. But has he gone too far? Critics say they're counting on Canadians to rise up and to stop what they say is a style of governing that threatens democracy.

"I think we're getting to the tipping point," Liberal MP Mark Holland said Wednesday.

"The precedent is so dangerous. If you have a government that gets away with this stuff, that gets away with purging any dissenting voices, purging anybody who disagrees with them, then how can we say that we have a democracy? It really cuts that deep."

New Democrat MP Joe Comartin was just as furious, saying he was disgusted by the news the RCMP is replacing a senior officer, Chief Supt. Marty Cheliak, who is responsible for the long-gun registry and who has been a strong advocate for the system. The Harper government is hoping a private member's bill to abolish the registry will pass when Parliament resumes sitting next month.

Comartin and others contend Harper wanted to silence Cheliak, so orders were given to RCMP Commissioner William Elliott to push him aside.

"It's all part of a pattern," said Comartin. "If they can't get their way, they try to bully and intimidate people into remaining silent. It's part of the obsessive, excessive control by the PMO, specifically by Mr. Harper and his immediate entourage. People are told you absolutely must toe the line on everything. That is very, very dangerous for democracy."

The governing Conservatives reject the accusation that dissenters are being punished. Rather, they note that every elected government has the right and responsibility to make staffing decisions. Moreover, they say that in many cases of supposed punishment, people are merely not having their terms renewed so they can be replaced with others who bring fresh ideas.

"The government appoints thousands of people and these appointments are for fixed terms," Harper's press secretary, Andrew MacDougall, said Wednesday. "They're not for life. And we always strive to appoint qualified people."

Also on Wednesday, Harper denied any political interference in the reassignment of Cheliak.

"This is an RCMP staffing matter. It's not a political matter," the prime minister said.

Still, critics are unimpressed and point to a growing list of examples of political interference. Among those affected:

- Linda Keen, president of the Canadian Nuclear Safety Commission, which shut down the nuclear reactor in Chalk River, Ont., over safety concerns. The government, worried about the impact on medical isotopes, said it had lost confidence in her and terminated her appointment in January 2008.