THE battle for Scotland's future stepped up a gear last night when business leaders publicly warned Alex Salmond that the "uncertainties" surrounding his desire for an independence referendum and the delay in holding it could seriously damage the nation's economy.

And in a clear sign the UK Government is now giving the issue of Scottish separation a higher priority, the "quad" of senior Cabinet ministers, chaired by David Cameron, met for the first time in Downing Street this week.

Last night one of its members, Chief Secretary to the Treasury Danny Alexander, said a standalone Scotland would have faced "catastrophe" during the financial crisis and its £14 billion deficit would have been one of the biggest in Europe. The ties between Scotland and the rest of the United Kingdom were "an essential cornerstone of our economic recovery", he insisted in a speech to the Scottish Confederation of British Industry.

In response, the SNP said the CBI had made a "politicised blunder" while it rebuffed Mr Alexander's claims, saying Scotland was in a stronger fiscal position than the UK.

The Chief Secretary's challenge to the SNP on independence followed one just 24 hours earlier from Michael Moore, the Scottish Secretary, who urged Mr Salmond to tell Scots how much a separate Scotland would cost.

The "quad" – the Prime Minister, his deputy Nick Clegg, Chancellor George Osborne and Mr Alexander – met in No 10 on Tuesday. Mr Moore joined them. "This week's speeches mark very much a shift in gear with Westminster upping its profile on the issue," a senior Whitehall source told The Herald.

"In the coming months, you can expect more ministers north of the Border saying why Scotland benefits from being part of the United Kingdom."

The source added: "There is a recognition we need to do more on this and get on the front foot. That's what you've seen this week and you will see more of it."

At the CBI dinner in Glasgow, Linda Urquhart, its chairwoman, addressed the First Minister's pledge to hold an independence referendum well into the second half of the Holyrood parliament – ie from 2014 – and highlighted the business community's concern about the "possible damage that could be done to Scotland by the uncertainties arising from this commitment and its timing. This is not helpful".

In his speech, Mr Alexander referred to Treasury number-crunching, which showed Scotland's share of the national debt in 2009/10 would have been around £65bn, "dwarfing" the Scottish budget, and warned the black hole in an independent Scotland's finances would get even worse as oil revenues dried up. "A further structural problem for Scotland would be just around the corner."

However, MP Stewart Hosie, the Nationalists' Treasury spokesman, who attended the dinner, attacked CBI Scotland, saying: "This is not the first time it has blundered into the constitutional debate and this latest intervention will fuel concerns the CBI's leadership has a political rather than a business agenda."

Responding to Mr Alexander, a spokesman for the Scottish Government said its figures showed "Scotland has now been in a stronger position than the UK as a whole for each of the last five years". He added: "The suggestion that Westminster's record debt is an argument against Scottish independence is a ridiculous one."