OTTAWA - Prime Minister Stephen Harper is looking for excuses to renege on his promise to call a public inquiry into the Mulroney-Schreiber affair, opposition MPs charged Friday.

Liberals and New Democrats levelled the accusation after the government refused to launch the promised inquiry until the House of Commons ethics committee tables its own report on the affair.

Liberal MP Paul Szabo, chair of the committee, tabled a brief interim report Friday, informing the House that the committee has finished hearing from witnesses and recommending that the government proceed with a public inquiry immediately.

Liberals simultaneously used an opposition day to turn up the heat another notch, presenting a motion urging the government to "immediately commence the public inquiry into the Mulroney-Schreiber affair.''

But the Tories steadfastly insisted an inquiry can't start until the ethics committee issues its final report, which is expected to take another couple of weeks.

"Surely, Mr. Speaker, after each member of the committee ... has spent so much time examining this issue, it would be foolish to commence an inquiry before the committee has had the opportunity to give its report,'' said Conservative MP Russ Hiebert, the government's point man on the ethics committee.

The government's refusal to expedite the launch of a public inquiry came one day after Brian Mulroney's lawyer said there is no need for a public probe into the former Conservative prime minister's private financial dealings with arms lobbyist Karlheinz Schreiber.

Mulroney originally called for an inquiry late last year, prompting Harper, who had initially rejected calls for an inquiry, to reverse himself.

Szabo said the government's refusal to quickly get on with an inquiry suggests Harper may be having second thoughts.

"It would appear that there is some back-pedalling on this matter,'' Szabo said.

Pat Martin, an NDP member of the ethics committee, said the government is using the committee as "an excuse to delay and stall.''

"I think probably the Conservatives are looking for any excuse to avoid a public inquiry at all,'' said Martin.

"Every day that we deal with the malfeasance associated with the Mulroney administration, it hurts the Harper administration. That's an unavoidable fact.''

No Tory MP directly suggested that the government may be reconsidering the value of a public inquiry. But Hiebert did reiterate the Tories' contention that the ethics committee has turned up no evidence of wrongdoing.

"Every witness, including Mr. Mulroney and Mr. Schreiber, confirmed for us that there was no wrongdoing with respect to these issues,'' Hiebert asserted.

"Nevertheless, Canadians are still left with a bad taste in their mouths because a former public office holder took large cash payments.

"While there may have been nothing illegal about the transactions, it certainly created the appearance of conduct that falls below the standard we expect of former prime ministers, as Mr. Mulroney himself acknowledged in his testimony. And he will have to deal with the shame of this matter for the rest of his life.''

Mulroney has admitted he accepted three cash-stuffed envelopes from Schreiber after stepping down as prime minister in 1993. He says he accepted $225,000 in total to lobby international leaders about a Schreiber-backed project to build German-designed light armoured vehicles in Canada.

Schreiber says the payments totalled $300,000 and that Mulroney was to lobby the Canadian government, which could have put him in violation of federal ethics rules.

Mulroney sued the federal government in 1997 after a justice official asserted, in a confidential letter to Swiss authorities, that the former prime minister was implicated in a kickback scheme involving Air Canada's purchase of a fleet of Airbus planes.

Jean Chretien's Liberal government eventually apologized to Mulroney and gave him $2.1 million in compensation. However, Chretien-era officials have said they wouldn't have settled had they known then about Mulroney's financial dealings with Schreiber, a lobbyist for Airbus.