When Stéphane Dion participated in mock debates in preparation for the real thing during the 2008 election campaign, the former Liberal leader said those playing his political opponents went after him with full force.

"Of course they did. I would have been unhappy otherwise," Dion said.

It's just part of the process that most if not all of the federal party leaders will have endured when they hit the stage Thursday night for the first campaign debate.

"They will have been in a rigorous debate prep process that's been in place for months, not weeks," said Scott Reid, former senior adviser to Paul Martin.

Reid said he has seen "a couple of leaders subjected to intense, tough, punishing rehearsals where their mock opponents really beat the living tar out of them."

Each candidate will have prepared in a way best suited to his or her own style, but the overall preparation is likely similar among the different camps, Reid said. The debate prep usually begins with assembling a team of trusted advisers, adding some outsiders to the mix, then moving people in and out in case they don't quite click with the rest of the team, or more importantly, the leader.

Then it's coming up with goals — does the candidate want to get by or decisively win — and assembling a playbook or briefing binder that includes debate cards categorized into different issues.

Dion, for example, said his debate binders included the main issues, the different parties' answers to those issues, how his opponents would attack his answers, and how he should respond. 

Don't 'look as if you're memorizing'

But Dion said it was also important to have written the answers out in his own words, "because you should not look as if you're memorizing when you're in a debate."

Initially, preparation sessions would be limited to about once a week, Reid said, or twice a month, usually taking place on a Sunday afternoon, or when there's some downtime.

All the while, the team strives for a consensus on objectives, the strengths, weaknesses, challenges and opportunities of the particular candidate, Reid said. And then, as the election nears, rehearsal time is booked.

That's for the mock debates, where the candidate faces off against staff or party members playing the roles of the other party leaders.

​"You can sit around the table, compare notes, have candidates roll off answers, all of that kind of thing," Reid said. "But until people have been forced to experience the physicality of the event, they won't thoroughly appreciate what success must look like.

"Getting them immersed in the setting is critically important. If they're just going to blow it off and say, 'I'm just going to look at my book, and that's all, and I'm going to be OK,' they'll face-plant."

Part of the mock debate process enables strategists to view their candidate's body language —  do they fidget, use their hands too much, are they looking at their opponent, looking at the camera? It's also about getting the candidate accustomed to the format (sitting or standing) and prepared for the time constraint of answers.

"You're rehearsing with your candidates to make them crisper and more focused and pare away the extraneous words that are distracting or eat up the clock," said David McLaughlin, the former chief of staff to Brian Mulroney.

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Former Liberal leader Stéphane Dion says that during preparation for the 2008 leaders' debate, he had binders that included the main issues, the different parties' answers to those issues, how his opponents would attack his answers, and how he should respond. (Adrian Wyld/Canadian Press)

Dion said a mock debate also gives a candidate the opportunity to improvise.

"During the mock debate I may improvise something that is good. Then we'll stop and discuss: 'Was it the best answer?' 'I'm surprised you said that.' Or, 'It may be badly interpreted.'

"This kind of situation will lead the team to interrupt the debate and to discuss what I just said."

It's also a good time to practise the so-called zinger — that biting, witty line that will knock an opponent down a peg and attract some good media buzz.

"If we have a punchline, the leader will practise it. And if we anticipate [an opponent's] punchline, we need a counterpunch and we need to practise it too," Dion said.

'Inner of the inner circle'

A mock debate also means that staff or party members will be put in the possibly awkward position of slamming their leader over politically sensitive subjects. 

"The people in the debate room are the inner of the inner circle," McLaughlin said. "They're the few of the trusted few.

"You need a candidate who is self-confident enough to take criticisms and you need staff who are self-assured enough to give criticisms, while being sensitive enough to know when to pump up the candidate as well as criticize the candidate."

Reid said that one person he did debate prep for was consistently uncomfortable with candid feedback.

"They did not finish well."

But the intense and hostile criticism of a mock debate can go too far, and Reid said in one instance it had the effect of rattling the candidate's confidence.

"You've got to be sensitive to the mood and dynamics of the candidate in order to get the candidate in the zone," McLaughlin said.