DAVID Cameron last night publicly caved in on the date of the Scottish independence referendum, paving the way for Alex Salmond to get his wish for it to be held in the autumn of 2014.

The Prime Minister said he was not "too fussy" about timing, but insisted the pro-UK forces could defeat the SNP not only on arguments of the head but also on arguments of the heart.

He said: "I know there is an enormous well-spring in terms of Scottish pride and Scottish nationhood and Scottish identity but I absolutely believe you can be prouder of your Scottish heritage, identity and all of that than you are of your British identity but still believe in this wonderful construction of the United Kingdom."

Mr Cameron's public declaration on the timing increases the chances that the First Minister will get the referendum on his preferred date after the 2014 Commonwealth Games in Glasgow and around the time of the Ryder Cup at Gleneagles.

The Prime Minister's comments came at a reception at the Scotland Office in London to mark the creation of the Scotland Act that gives Holyrood extra tax powers – and appeared to take some ministers by surprise. They have repeatedly and consistently said they did not want to wait more than two years and wanted it "sooner rather than later".

He said: "I'm not too fussy about the timing but let's have a simple question, let the question be put, but above all let's make sure we keep our United Kingdom together."

Last month, he used a similar phrase but qualified it heavily by asking: "For Heaven's sake, is it really right for the Scottish people to have to wait 1000 days to be asked this question?"

Following these remarks, Downing Street was adamant the Coalition line had not changed, with the PM's spokesman making clear the UK Government wanted the poll as quickly as possible.

Only last week, Michael Moore, the Scottish Secretary, told The Herald the two-year delay to 2014 was damaging to business investment in Scotland and it was the Coalition's firm policy to have the referendum next year.

Bruce Crawford, the Scottish Government Secretary for Parliamentary Business, said: "I am delighted the Prime Minister has now conceded the timescale for Scotland's referendum."

A senior Scottish Government source told The Herald Mr Cameron's remarks were a major development but denied any private quid pro quo had been done with Mr Salmond on securing just one question on the ballot paper. He stressed this matter too must be decided at Holyrood.

Mr Crawford added: "The terms and the timing of the referendum are matters to be decided in Scotland, not imposed by Westminster."

Mr Cameron said that not only

could the pro-UK forces win the arguments of the head on jobs, defence and business, but also of the heart, suggesting that the so-called "Braveheart" arguments could be defeated.

He highlighted the eurozone crisis as an example of why Scotland should remain part of the UK.

Mr Cameron said: "You need look no further than the great success of the Union and the United Kingdom that we have created here in these islands."

l Alex Salmond last night told Scots-born American television interviewer Craig Ferguson that an independent Scotland would retain the "firmest and strongest" of bonds with the United States.

He was speaking during CBS network chat show The Late Late Show with Craig Ferguson.