A couple who won £161million on the EuroMillions lottery have given another £1 million to the SNP, taking their total contribution to Scottish independence campaigners to £5.5 million.

Chris and Colin Weir donated £500,000 each to the Scottish National Party on February 10, the Electoral Commission's register of donations for the first three months of this year has revealed.

That comes on top of another £1million they donated to the SNP in September 2011, and the £3.5 million they have donated to the Yes Scotland campaign over the last two years.

Labour received £4,409,167 with two-thirds of it coming from the unions Unite, Usdaw and Unison, while the Liberal Democrats received a total of £1,074,482.

An SNP spokeswoman said: "We thank all of our donors - big and small - for contributing to the success of the party."

Labour constitutional spokesman Drew Smith said: "The Weirs are entirely entitled to spend their lottery winnings as they wish but the revelation that the SNP and the Yes campaign are relying on just one family for their funding does rather undermine the Nationalists' claims of a broad-based grassroots campaign."