A BULLISH Alex Salmond has insisted that his widely attributed win over Alistair Darling in the second head-to- head debate will carry the pro-independence campaign to victory in next month's referendum.

The First Minister renewed his challenge to David Cameron, who is expected in Scotland later this week, to a TV debate. A senior Whitehall source ruled out the prospect of a PM/FM clash, saying the Prime Minister would not reconsider his rejection of Mr Salmond's offer.

After the majority of pundits gave Monday night's 90-minute debate to the SNP leader, he was in an upbeat mood, saying: "The Yes campaign are going to have our tails up and our tails will be up for the next three weeks as we carry this campaign to victory."

Mr Salmond claimed the leader of the Better Together campaign had "muffed" his chance and branded the former Labour Chancellor a Tory frontman.

"He is in alliance with the Conservative Party in this campaign; that is what the No campaign is," declared the FM.

"Let's have the real leader of the No campaign, David Cameron. Let's have him in Scotland now, let's see if he can do any better than Alistair Darling did. I don't think he will. Let's see if Mr Cameron is prepared to come to Scotland and have the debate," said the FM.

Asked for Mr Cameron's view on the Salmond/Darling debate and whether or not he was concerned the momentum was now with the Yes campaign, the PM's spokeswoman said: "The PM watched news reports of the debate last night.

"He believes staying in the UK means Scotland keeping the pound and having the best of both worlds."

The PM watched highlights of the first head-to-head but asked why he had not watched the second one, given its importance in the campaign, the spokeswomen replied: "The point is he watched the reports of the debate; he saw the main elements of the debate," stressing: "The key moment is when people go to vote on September 18."

Asked what level of engagement voters could expect of Mr Cameron from now until polling day, the spokeswoman replied: "It's clearly for the people of Scotland to make their choice in the referendum and the Prime Minister's role is making sure that they are as informed as possible about the decision they're making."

Later, a No 10 spokesman said: "Following last night's debate the Prime Minister concluded that the First Minister still has no answers on currency or how to fund public services while relying on volatile and declining oil revenues. It remains the Government's position that Scotland can enjoy the best of both worlds; the security of being part of something bigger without the risk and uncertainty of separation."

But Yes Scotland was scornful of Mr Cameron's decision not to watch the Salmond/Darling debate, saying he had "ignored the TV debate watched by milllions throughout Scotland and the rest of the UK".

Its spokesman said: "Perhaps David Cameron is distancing himself from the faltering No campaign. After all, he has snubbed all exhortations thus far from people in both camps to come to Scotland to debate with First Minister Alex Salmond.

"He is expected to journey north of the Border soon - and frequently up to referendum day - so could very easily respond positively to an open invite. However, he and his colleagues on the No side don't do positive, as everyone saw by the abysmal performance of Alistair Darling during the second televised debate," he added.

Meantime, a source close to the FM said: "David Cameron may not have been paying attention but the London Establishment is now starting to wake up to the fact this referendum campaign is going right down to the wire and it is the Yes campaign which has all the momentum."

He added: "That will only increase the pressure on the No campaign now that their bluff has been called on currency, the funding threat to the NHS from Westminster has been made even clearer and their failure to come up with any alternative job-creating powers has been exposed."