A MEMBERSHIP surge since the independence referendum has left the SNP less reliant on big-money donors with income from membership subs more than doubling in 12 months.

New accounts lodged with the Electoral Commission show that the party earned £2.7m in membership income in 2015, rocketing from £1.3m the previous year and contributing towards a healthy surplus. Following the Yes campaign's defeat in the September 2014 referendum, party membership rose from around 25,000 on the day of the vote to more than 100,000 by the following March.

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The rise partially offset a large drop in donations, from £4.4m in 2014 to £1.5m last year, when most of the cash came from Euromillions winners Chris and Colin Weir in the run-up to the general election. The campaign saw the party hire a SNP-branded helicopter to take Nicola Sturgeon across the country.

Mr and Mrs Weir, who are lifelong supporters of independence, gave the party £1m in 2015, but between them donated double that sum in the months before the referendum.

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Overall, the party reported income of just over £6m last year, around £550,000 more that it spent. The surplus left the party with £70,000 in reserves, a turnaround from last year when it reported a cash deficit of £485,000.

In 2014, the SNP spent £7.2m - around £250,000 more than came in - while in the previous 12 months it earned just £2m. Reflecting on the party's huge increase in financial muscle, an SNP spokesman said: "We are grateful to all supporters for contributing to the ongoing success of the SNP."

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Other sources of income last year for the party included £300,000 from fundraising and grants of £175,000. Conferences made the party £750,000 in income, although they cost £664,000 to stage. The SNP's Westminster accounting unit, which operates separately from the central party, reported £614,000 in income and just £564,000 in expenditure.

Meanwhile, the Scottish Greens did not report a similar surge in membership income, despite seeing a larger rise in numbers percentage terms than the SNP. Its accounts revealed that it earned £183,000 in membership income in 2015, an almost identical sum to the previous 12 months.

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The Scottish Greens spent £404,000 last year, around £15,000 more than it earned in the period, but remains in a comfortable financial position having made surpluses in previous years.

In 2015, the SNP's income of £6m was around £200,000 more than UKIP's and double that of the Green Party of England and Wales. The Liberal Democrats reported income of £7.9m, compared to the Conservatives' £42m and Labour's £51m.