The Scottish National Party has threatened to call for another referendum to break up the United Kingdom unless the British government agrees to devolve more powers to Scotland, the Financial Times reported on Monday.

In an interview with the newspaper Stewart Hosie, the SNP's Treasury spokesman in Westminster, said that if London failed to go further than the package of devolution measures already on the table another ballot could be triggered within a few years.

Lawmakers are scheduled to debate those measures in the House of Commons on Monday, with SNP lawmakers pushing for amendments to allow the Scottish parliament to claim new powers.

Voters in Scotland rejected independence in a referendum in September last year, ahead of which the SNP's leader at the time said the vote was a once-in-a-generation opportunity to break the three-century union with England.

Hosie's comments were the first from the SNP to link the issue of devolution with another independence vote, the FT said.

Scotland's First Minister Nicola Sturgeon told British Prime Minister David Cameron this month that he could provoke another independence vote if he failed to keep Britain in the European Union at a referendum he plans to call before the end of 2017.

Hosie told the FT about a second possible scenario for a new vote: "If the public - particularly those who voted 'no' (in last year's Scottish referendum) think they've been sold a pup because what has been promised does not go as far as...the unprecedented programme of devolution promised by the prime minister."