The Scottish National party (SNP) candidate for Glasgow East provoked anger and confusion yesterday by insinuating the party would keep on holding referendums on Scottish independence until it got the answer it wanted.

“When you ask someone to marry you, sometimes you have to persist,” said John Mason.

He then quickly asserted that he did not expect another referendum “the following day” if the nationalists lose the next one.

The view contradicts statements made by his party leader, Alex Salmond, who described independence referendums as a “once in a generation” event.

Mr Mason is considered a hard-liner in the SNP, but he has made distinct efforts to appear unified with Mr Salmond’s command.

It is the first time independence issues have had an impact on the by-election, in which Labour’s strong 12,000 majority is under threat from a galvanised nationalist campaign.

David Cairns, the Scotland Office minister, said: “These comments prove councillor Mason is more hard line than Alex Salmond. He is the extreme face of nationalism.

“It demonstrates he is obsessed by one issue only, to the exclusion of the concerns of ordinary people in the East End.”