Coached to win: How Alex Salmond and Alistair Darling will be preparing for tonight’s Scottish independence TV debate

Glasgow-born Coia, the first voice ever heard on Channel 4, said: “They will be under pressure but they will have been coached to within an inch of their lives.

“Salmond’s team and Darling’s team will be – if they’re any use – preparing them for every single possible question that can come up. None of the answers that they give tonight should be a surprise to them or made up on the spot or have them floundering.

“If there are any surprises tonight somebody hasn’t done their job.”

To win over viewers and voters, Coia feels both first minister Salmond and Better Together figurehead Darling will have to control some of the tics that have categorised their campaigns.

For Salmond that means keeping a lid on his trademark bullishness, while Darling will have to put on a more positive front than Better Together has managed to portray so far.

“I think Alex Salmond will have to temper some of his usual style,” Coia said. “If Alistair Darling is too laidback it’s going to look like Alex Salmond is some sort of shouty man. I think people have had that strident Alex Salmond and they don’t like it. Certain people do but the majority don’t.

“At the opening of the Commonwealth Games I thought Alex Salmond delivered his speech in a very statesmanlike way – he didn’t shout, he didn’t try to score political points. He behaved like a statesman. I think he should go for more of that kind of style tonight.”

Darling, a respected politician but not one renowned for charisma, should not be afraid to inject emotion into his answers, according to Coia.

“It’s not just about the words. It’s not just about the argument. It’s about the posture, the smile on their face when it’s appropriate. Yes it’s politics, yes it’s a very serious subject, but you don’t have to look as if you’re going to your own funeral the whole way through.

“Look statesmanlike. But part of being a statesman is reflecting all emotions and all people’s thoughts. Don’t be monotone. Do it in five-channel stereo with all the emotions going. But don’t be strident. Strident turns people off.

“If you only do the negative messages people tend to think ‘oh hang on a minute, you think we’re stupid, you’re trying to scaremonger, we’ll show you…’ You can’t go down that route in any debate.”

So what final words of advice will be ringing in their ears as they make their way up to the podium? “What the advisers will be saying to them now is: do not sound equivocal, do not sound like you don’t know what you’re talking about, hang your hat on this and go for it. Be definite. The time for bumbling and making it up has gone.”

It is not just a huge night for Salmond and Darling, but also for the veteran STV political editor Bernard Ponsonby, who has been given the sizeable task of separating the two warring factions as moderator.

“It’s huge for him,” said Coia, who spent several years at STV at the beginning of his career. “It gives him a profile well beyond the one he would have had locally in Scotland. He’ll be prepared like they will be prepared and he will have done his homework. He’s very knowledgeable and I have no doubt whatsoever that he will be able to steer it in the way it should be steered.”

Despite Ponsonby’s professionalism and the two protagonists being so well mentored – Alex Salmond has reportedly been taking lessons from a ‘happiness guru and lifestyle coach’ – Coia believes there is still room for fireworks in tonight’s programme.

“The drama will come from them – if they’re clever enough – using emotions. It won’t come from surprising questions or if it does, somebody needs firing.”

The Drum's media blogger Chris Boffey had earlier argued that tonight's historic debate should also be shown in England. While it won't be televised south of the border, those outside Scotland can watch it online.