OTTAWA - Karlheinz Schreiber wasted no time claiming star billing at a public inquiry Tuesday, opening his performance with a promise to tell all he knows about the scandalous behaviour of Brian Mulroney's former Conservative government.

By the time the curtain fell, however, Schreiber was the one on the hot seat as commission counsel Richard Wolson questioned his credibility and his motives in promoting a project to build German-designed armoured vehicles in Canada.

The swift reversal of fortune came as Schreiber, in his opening day of testimony before Justice Jeffrey Oliphant, recounted how he made a deal with Mulroney to bring him on board as a lobbyist for the project once he'd left the prime minister's office.

The deal, supposedly struck at a 1993 meeting at the prime minister's summer residence on Harrington Lake, lies at the heart of the inquiry into the business dealings between the two men.

But Wolson noted pointedly that, in previous testimony in a 2004 court case, Schreiber played down his personal contacts with Mulroney and never even mentioned the Harrington Lake meeting.

"When you were asked under oath, you left it out," Wolson declared.

The 75-year-old German-Canadian businessman chalked that up to a misunderstanding. In 2004, he said, he thought he was being asked only about meetings involving a European helicopter company that then faced criminal charges.

"You didn't want to tell the prosecutor that you had a relationship with Brian Mulroney," Wolson persisted.

"That is not true," Schreiber shot back. But his defensive posture was a sharp turn-around from the bravado he had exhibited as he entered the hearing room.

"If you think we have one scandal, no," Schreiber told reporters. "The secret is it's seven scandals in one. You can count on me. I'm not going to disappoint."

Once he was sworn in, Schreiber insisted that, if the so-called Bear Head project had gone ahead and Ottawa had bought the armoured vehicles designed by Thyssen AG, Canadian soldiers wouldn't be dying today from roadside bombs in Afghanistan.

"This is my huge anger," said Schreiber. The issue, he contended, is not the "few bucks in commission" he made from his promotional efforts for the project.

"It is about lives. . . . Do you read me, sir? This is my whole war with this government."

That outburst drew a sharp rebuke from Wolson, who advised Schreiber to stick to answering the questions posed -- and to remember that more than a few bucks were at stake.

Under prodding by the inquiry counsel, Schreiber acknowledged that he stood to receive $6.5 million in "success fees" from Thyssen for his work.

Some of that money -- an estimated $610,000 -- was passed on by Schreiber to Canadian lobbyists who had close ties to Mulroney. Among them were former Newfoundland premier Frank Moores, former Mulroney aide Fred Doucet, his brother Gerry, and one-time Tory backroomer Gary Ouellet.

The stakes would have been even higher if Thyssen had been able to use Canada as a manufacturing base to capture a wider export market for its vehicles, said Schreiber.

Under those circumstances, "it would have been a project in the neighbourhood of $360 billion (for Thyssen). And I would have received, out of that, at least $1.8 billion."

The original plan, outlined in 1987-88, called for Thyssen to build a vehicle manufacturing plant in Cape Breton. The proposal met with skepticism from the Defence Department, but Schreiber said Mulroney never expressed anything but support to him.

"When I had all these fights with DND, he always told me I should hang on, it's going to happen. . . . Mr. Mulroney wanted the project very much."

Documents tabled at the inquiry show that, by 1992, the proposed location of the plant had shifted from Cape Breton to Montreal and preliminary discussions were being held to bring the Quebec government of then-Liberal premier Robert Bourassa onside.

Schreiber maintains that he reached an agreement in principle, during the June 1993 session at Harrington Lake, for Mulroney to lobby for the modified project after he departed from government.

Wolson was incredulous, wondering how Mulroney could exert any influence in retirement when he hadn't been able to push the project through while he was in power.

"When he was prime minister Bear Head never happened," said Wolson. "It never happened in Nova Scotia, it never happened in Montreal"

Schreiber insisted that, nevertheless, he was hopeful Mulroney could clear a political path for the project -- if not at the federal level, then perhaps by lobbying the Quebec government.

In testimony before a Commons committee in November 2007, Schreiber said his payments to Mulroney eventually totalled $300,000. But he complained the former prime minister did little to earn the money, delivered in cash-stuffed envelopes in a series of hotel-room meetings.

Mulroney acknowledged before the same committee that he accepted cash from Schreiber, but put the total at $225,000 and insisted his lobbying was limited to foreign leaders whose countries might have bought the Thyssen vehicles.

The distinction between domestic and foreign lobbying is a key one, since Mulroney could have run afoul of federal conflict-of-interest rules for lobbying at home.

The former prime minister isn't expected to testify until next month, but spokesman Robin Sears offered a thumbs-down review of his chief accuser's performance Tuesday.

"When Mr. Schreiber is testifying under oath he's much less colourful a story-teller than when he isn't," said Sears.

Schreiber's testimony is expected to take up most, if not all, of the remainder of this week's hearings.