The Scottish National Party received a £1.4 million boost from its two biggest donors in the final weeks of its independence campaign, new figures show.

EuroMillions winners Chris and Colin Weir donated £500,000 each on September 5 after donating several million more in the months leading up to the September 18 poll.

And bus tycoon Brian Souter donated £400,000 two days before the referendum.

The donations made the SNP the fourth biggest ­recipient in the UK in the three months to the end of September, collecting roughly half of the money taken by the entire UK Labour Party (£3.2m) and just less than one-quarter of that taken by the UK Conservatives (£6.7m).

The SNP is still the biggest UK fringe party once the Weir and Souter donations are excluded, with an additional £172,825 received, nearly twice as much as Ukip (£98,387) and the Green Party (£88,250).

An SNP spokesman said: "As membership of the SNP surges to over 84,000, the party has never been in better shape. We are very grateful for every donation - large and small - from our supporters which all help us to campaign and work for Scotland."

Scottish Conservative deputy leader Jackson Carlaw said: "This makes a mockery of the idea the SNP is a grass-roots organisation. The facts are the party and the associated Yes campaign were bankrolled by a couple who picked their lucky numbers and a businessman with whom the party is almost too embarrassed to be associated."