OTTAWA - The Harper government's political opponents are accusing Conservative MPs of using government advertising and communications - paid for by all taxpayers - to advance their own partisan interest.

The NDP is so incensed, it has asked parliamentary ethics commissioner Mary Dawson to launch an investigation.

Both the NDP and the Liberals are upset about some recent advertising and public relations initiatives they say veer over the line separating appropriate communications about government projects and partisan appeals for political favour.

"What's becoming apparent is that the Conservative stimulus program is biased, unfair, targeted to Conservative ridings and shameless in the way it uses party logos to promote a stimulus program that ought to benefit all of Canadians," Liberal leader Michael Ignatieff said in Regina on Wednesday.

Conservative MPs have been orchestrating cheque-presentation ceremonies, in which the oversized ceremonial cheque contains the picture of the MP, the signature of the MP, Conservative Party logos or a combination of all three.

One of those MPs, Nova Scotia's Gerald Keddy, said the $300,000 cheque he presented for an arena upgrade mistakenly contained his party's logo and he could not explain how his signature ended up on the cheque.

"I think the member (of Parliament) in question admitted that was a mistake and should not be repeated," Prime Minister Stephen Harper said Wednesday while visiting Edmonton.

"So Keddy's not going to do it again, but what about the rest of them?" said NDP MP Peter Stoffer. Stoffer filed a complaint with the ethics commissioner this week. "It blows me away that they could be so blatant, using your tax dollars to promote themselves."

The NDP and Liberals say they have dozens of examples where a Conservative MP hands over what Liberal MP Wayne Easter called "government of Canada cheques disguised as Conservative cheques."

In one case, B.C. Conservative MP Colin Mayes handed over a cheque with the Conservative party logo and his own picture on it.

In Ontario, Conservative MPs Scott Reid and Larry Miller dispensed with party logos altogether, but put their own names in large print in the top left corner of ceremonial cheques they posed with, making it seem as if the cheques were drawn on their personal accounts.

"These are the tax dollars of Canadians," said Easter. "They're not Conservative dollars . . . just to be used for the Harper propaganda and messaging machine."

Ignatieff said the Conservatives' political posturing risks tarnishing the infrastructure program.

"We're in the most serious economic crisis in 30, 40 years, and my party voted for a stimulus package that would benefit all Canadians, not just Conservative ridings," he said.

"And we voted for a stimulus package that would go out on the Government of Canada, not the Conservative Party of Canada. And I think Canadians are rightly angry about it."

Stoffer, who has been an MP for more than 12 years, said he could not recall previous Liberal governments - despite the excesses that led to the sponsorship scandal - engaging in that behaviour. When Liberal governments held ceremonial cheque presentations, Stoffer said, the cheque looked like the kind any senior might receive for old-age security: It read "Government of Canada," was signed by the receiver general of Canada - a bureaucrat - and did not have any political markings on it at all.

"The Conservatives said they would do things differently, and, in fact, they've done things in reverse," said Stoffer.

The government has also changed the way it describes itself in news releases announcing new funding or program initiatives.

Instead of referring to itself as "the Government of Canada," news releases issued by non-partisan bureaucrats are now appearing with that phrase replaced by "the Harper Government."

Indeed, the National Research Council announced $1.5 million in funding Wednesday to support product development at an Oakville, Ont., company, and the news release read: "Harper Government Supports Innovative Research and Development in Oakville."

Stoffer said such a change is wrong.

"It is against all the ethics we've been trying to do here in Canada," Stoffer said. "This is your tax money. It's not to promote the government in power."

The Liberals also attacked the Harper government Thursday for abandoning a process that would depoliticize the public appointments process.

Liberal researchers said that, in the last six weeks, three dozen government jobs were handed out by Harper's office to people with close Conservative connections.

"It's a startling illustration that Stephen Harper is addicted to the political patronage he promised to prevent," said Easter.

Harper first won office in 2006 on a platform that included a promise to depoliticize the appointments process. He offered to do that with a new public appointments commission, an arm's-length body that would review the thousands of appointments the federal cabinet makes each year to government corporations, agencies and tribunals.

The Liberals Wednesday zeroed in on three "all-in-the-family" patronage appointments to illustrate their point.

Doug Finley, the husband of Human Resources Minister Diane Finley, was appointed to the Senate; Judy Dreeshen, the wife of Alberta Conservative MP Earl Dreeshen, was appointed to a Canada Pension Plan Review Tribunal; and Kelley Sherwood, the wife of former PMO communications director Kory Teneycke, was re-appointed to the pension plan review tribunal.

Sherwood was initially appointed three years ago, before Teneycke joined the PMO.