Scottish Labour leader Richard Leonard has claimed there could be a swing of undecided voters toward his party.
Mr Leonard told the PA news agency people will realise as the election nears there is a “stark choice” between Labour and the Conservatives.
Polls in recent days have showed the Labour vote rising, closing the gap with the Conservatives in UK-wide voter intention.
A Survation poll published on Monday showed a rise of three points to Labour, up to 33%, while the Tories rose by one point to 42%, compared with another study done on November 23.
But last week, an Ipsos MORI survey for STV showed support for Labour had slumped in Scotland to just 16% of the vote.
Mr Leonard said he takes polling “with a pinch of salt”, adding most do not record undecided voters, which he claimed could result in a “skewing” of the study.
He said: “There’s a technical point about polls, they don’t record undecided or ‘don’t knows’, so there’s a potential skewing of results coming from polls which doesn’t reflect where people are.
“I’m still knocking on doors where people haven’t made their mind up yet.”
Mr Leonard said a high proportion of undecided voters could mean a boost for his party.
“In the end, the choice is a stark one, the election of a Tory Government for five more years or the election of a Labour one,” he said.
“There is no shortcut to the election of a Labour Government through any other party.
“The SNP say that their ambition is to deprive the Tories of their majority, we don’t want to just deprive them of their majority.
“We want to form an alternative Government that would change the way that our economy and our Government works.
“We want to see radical change, and it’s possible with the election of a Labour Government that could start this side of Christmas.”