THE pro-independence campaign is believed to be just days away from laying bare details of its donors after its pro-UK rivals unveiled a £2 million war chest swelled by generous backing from business leaders.

Yes Scotland is understood to be planning to respond to the Better Together campaign, which yesterday revealed who was funding it in the run-up to the poll on September 18 next year.

The group's Blair Jenkins criticised Better Together, led by former Labour Chancellor Alistair Darling, for accepting large donations from benefactors not based in Scotland.

These numbered a £25,000 gift from Douglas Flint, the Glasgow-born chairman of HSBC, and £161,000 from Edinburgh-born crime writer CJ Sansom, who described the SNP as "dangerous" in a note appended to his recent novel Dominion.

News of Mr Flint's donation prompted a number of Nationalist supporters to threaten to take their cash out of HSBC, despite it being praised last week as "the most Scottish bank in the world" by Alex Salmond.

In total, Better Together announced a £2m war chest, including uncollected pledges of £1m. Ten single donations – most from leading business figures – amounted to £891,000 out of £1,118,451 banked so far.

The largest cheque came from oil trader Ian Taylor, chief executive of Vitol. The long-standing Tory donor said he was "delighted to be in a position to help" the campaign.

Engineering entrepreneur Alan Savage donated £100,000; Peterhead businessman Charles Richie, of Score Group, gave £50,000; and Aberdeen property developer Alan Massie donated office space worth £15,000.

The late Gordon Baxter, of Baxters Food Group, ex-Christian Salvesen chairman Sir Gerald Elliot, and the co-founders of Artemis fund managers Mark Tyndall and John Dodd each contributed £10,000. A further 27 donors gave amounts of between £500 and £7500, resulting in a total of £54,066.

The bulk of the donors gave under £500, with 9464 people handing over a total of £173,385 – an average of £18.26 a person.

Blair McDougall, campaign director, said: "We are humbled that, in difficult economic times, almost 10,000 people have chosen to make a contribution to our campaign. We have not received a penny from political parties.

"Every penny we have raised, we have raised ourselves from supporters of our cause.

"Ten thousand donations is a good start, and we have plans to raise far more as we fight for the future of our country."

A spokesman for Yes Scotland said: "We believe the appro-priate position is that both campaigns should agree that any donations above £500 – the legally recognised level over which money given becomes a 'donation' – should come only from those registered to vote in Scotland's referendum.

"We contacted the No campaign some time ago suggesting both parties should agree to release donations information simultaneously, but we received no response from Mr Darling or his staff. Yes Scotland will be releasing its figures on donations soon."

Spending by the two sides will be capped at £1.5m during the final 16 weeks of the campaign before the referendum. Political parties will also face limits based on their number of MSPs. Till then, campaigners and parties are free to spend as much as they can raise.

Better Together has rejected calls from Yes Scotland to accept large donations only from Scottish-based sources.

Meanwhile, Sir Gus O'Donnell, the former head of the civil service, called for the creation of an impartial commission to assess pledges and spending commitments made by both campaigns. The idea follows repeated calls for greater clarity and details in the referendum debate.