Scottish Secretary David Mundell has claimed the test for Nicola Sturgeon at the general election will be whether the SNP can match its 2015 performance.
The Tory frontbencher insisted an outcome of fewer than 56 seats or a decreased share of the vote would show that momentum was not with the first minister.
He also talked up his party’s prospects in the north-east and described the Conservatives as the “challengers to the SNP”.
But an SNP spokesman accused Mr Mundell of “getting his excuses in early for losing”.
And he defied the Tories to “stop blocking” a second poll if they lost in Scotland.
Mr Mundell, who represents Dumfriesshire, Clydesdale and Tweeddale, is currently Scotland’s only Conservative MP. But polls over the weekend suggested the party could win eight to 12 seats on June 8.
He told the Press and Journal: “Only hard work wins seats, so we are not getting carried away by polls, but they are reflective of a trend which confirms the Scottish Conservatives are the challengers to the SNP.”
He added that Scottish Tory leader, Ruth Davidson, had emerged as a “real opponent”, someone who can “not only stand up to the SNP, but take seats off them”.
He refused to make predictions in terms of numbers or comment on specific seats, but added: “I think – particularly in the north-east – there is real scope for the Conservatives to make progress building on the fantastic result we had in the Scottish Parliament election.
“The test for Nicola Sturgeon is: does she return 56 MPs, does she achieve 50% of the vote, does she achieve 1.5 million votes? That’s what she did in 2015.
“In my view, any diminution on any of those numbers actually demonstrates that the momentum is not with those campaigning to have another independence referendum.
“Reduced representation at Westminster is not a mandate to have another independence referendum.
“The constitutional issue is suffocating Scottish politics and important other issues are just being crowded out by the SNP’s obsession.”
An SNP spokesman responded: “This is a ridiculous suggestion from David Mundell, who is getting his excuses in early for losing.
“Only the SNP will stand up for Scotland’s interests at Westminster.
“There is already a cast-iron democratic mandate, backed by a vote of the Scottish Parliament, for Scotland to be given a choice on its future.
“The challenge for the Tories is: if they lose the election in Scotland, will they stop blocking a referendum?”
