Our political correspondent Stewart Paterson gives his verdict on the TV performances.

In the first debate, Mr Salmond was considered to be below par and allowed Alistair Darling to put him on the back foot on currency.

This time, the First Minister's ice bucket challenge at the weekend seemed to have invigorated him more than his opponent as he not only provided more coherent answers but went on the attack more effectively on the NHS, poverty and nuclear weapons.

Mr Darling decided he had a winning formula by asking for a Plan B on currency but perhaps laboured too much on it instead of challenging just as forcefully on other aspects of the yes campaign.

Questions from the audience seemed to put pressure on Mr Darling rather than the First Minister who became more emboldened as the debate went on.

Mr Salmond went on the front foot early on and was first to interrupt when the other was speaking and moved out from behind the lectern to address the audience in a more direct manner.

Mr Darling was strongest on arguing that oil was volatile and Scotland's budget would be more dependent on it than the UK is as a whole.

Mr Salmond was still able to come out of the exchange well by stating the very fact so much oil existed was a blessing, not a curse.

The audience reaction suggested Mr Salmond had got his point across much more effectively this time and has recovered from the perception that Alistair Darling was the 'winner' in the first debate.

I don't know exactly how you judge a winner in a television debate and how much it will influence the overall outcome on September 18, but on articulating the argument and gaining support from the audience then Mr Salmond would have to be considered the victor.