Federal Health Minister Ujjal Dosanjh said Sunday that he won't step down from cabinet over the Grewal affair.

A day after Prime Minister Paul Martin called for those involved in the secret tapings of conversations between the Liberals and a Tory MP to co-operate with a federal investigation, Dosanjh told CTV's Question Period that he did nothing wrong.

"I'll be happy to co-operate with the RCMP and their inquiries, and with the Ethics Commissioner and his inquiries, and I'll be happy to live by the results," he said in Vancouver during an interview with Question Period's Jane Taber.

"And I believe that at the end of the day it's important that we respect the institutions of Parliament. That we make sure that members of Parliament can talk to each other without being surreptitiously taped."

Dosanjh and the prime minister's chief of staff, Tim Murphy, were apparently caught on tape offering rewards to Gurmant Grewal, a Conservative MP.

The recordings purport to show Grewal engaged in negotiations with the Prime Minster's Office about him and his wife, also an MP, leaving the Tories -- in exchange for possible political favours and for his help during a crucial vote in the House of Commons.

"We were living in a time when government was in danger of losing the vote. Most Canadians didn't want Parliament to not work," said Dosanjh, explaining what prompted him to agree to speak with Grewal in the first place.

"When you have an offer coming through a third party from someone who says ... he's prepared to walk across the floor without any demand, I would talk to any parliamentarian under those circumstances. That's how those conversations began."

Conservative Strategist Tim Powers, meanwhile, said "It appears there was a fire sale going on in the Liberal Party."

"And Gurmant Grewal, perhaps using some unconventional techniques, discovered that."

Powers, who was part of a Question Period panel discussion with Liberal and NDP strategists, claimed the tapes clearly show Dosanjh and the prime minister's chief of staff making plum political offers to Grewal.

"It's hard for people to believe that both Ujjal Dosanjh, who was a former attorney general of British Columbia, and Tim Murphy, who was a practicing lawyer, would even involve themselves in this escapade," he added. "That's striking, that's upsetting and it was totally inappropriate."

The Liberals have claimed that the tapes were doctored, after audio expert Steven Pausak pointed out a break in audio in one of the tapes.

Conservative Leader Stephen Harper has denied there was any doctoring, and said unless an investigation shows otherwise, Grewal has done nothing wrong and deserves praise for coming forward.

Portions of the tapes released by Grewal show the Liberals were courting him, but they don't include any specific commitments or indicate who initiated the conversations.

While Grewal has claimed that Dosanjh approached him, the health minister maintained Sunday that he "absolutely did not call" Grewal. He said Grewal approached him through a third party.

Ethics Commissioner Bernard Shapiro announced this week that he will open a formal investigation into the recordings into whether Dosanjh offered inducements to Grewal to change his vote, and whether Grewal improperly sought such inducements.