OTTAWA - To paraphrase ancient Chinese military strategist Sun Tzu, knowing yourself is knowing your enemy.

Michael Ignatieff may be brushing up on his.

Stashed on a bookshelf at Liberal headquarters is an insider's account of Stephen Harper's rise to the prime minister's office -- the Tom Flanagan book, Harper's Team.

Ignatieff's own team may be looking to crib from the former Harper campaign manager's play book.

Flanagan writes about the Conservatives getting their message out early during the 2006 campaign to force the Liberals to respond to them.

And so the Liberals were at it early Saturday. A statement from Ignatieff -- issued about 30 minutes before the election date was even announced -- tried to blunt the main Tory attack line: namely, that the Liberals are in bed with socialists and separatists.

Ignatieff said he's open to working issue-by-issue with other parties if his party wins the election. But he "categorically" ruled out a coalition or even a formal arrangement with the Bloc Quebecois.

The coalition question has threatened to dog Ignatieff during the campaign as the Conservatives frequently raise the spectre of a cabal with the NDP and Bloc Quebecois.

Ignatieff spent most of the day campaigning in Ottawa.

He invoked Bob Dylan's song "Gotta Serve Somebody" at a rally at a downtown Ottawa hotel packed with Liberal supporters.

"Bob Dylan has this wonderful song," he said. "Some of you know it ... it has that wonderful line in it, 'everybody's gotta serve somebody."'

"We've got to know in this election who we serve," he said.

It was a not-so-subtle dig at Harper, who the Liberals are trying to cast as a power hungry control freak.

The Liberal leader seemed at ease as he spoke for about 15 minutes to a packed ballroom of supporters. His stripped off his jacket, rolled up his shirt sleeves and spoke without any notes.

He also revealed a hidden ambition: to drive a bulldozer.

Ignatieff told the crowd about a woman he met in Newfoundland who wanted to drive a bulldozer but couldn't because she wasn't able to get child care for her kids.

"When I think about who I want to serve I think of a wonderful young woman I met a couple of weeks ago in Newfoundland," Ignatieff said.

"She said to me, 'you know what I want to be, I want to be a bulldozer driver. And I said, you go girl because you're going to achieve a dream I've had since I was a child."'