Scottish Conservative leader Ruth Davidson believes her party can increase its share of the vote to nearly half a million on Thursday.
More than 400,000 people backed the Tories in 2010, but that only translated into one seat, Dumfriesshire, Clydesdale and Tweeddale.
Ms Davidson, speaking on a cross country tour yesterday, insisted her party could do better in 2015 and is best placed to defeat the SNP in West Aberdeenshire and Kincardine – a north-east constituency held by the Liberal Democrats since 1997.
And while the Glasgow MSP said she does not condone tactical voting, she encouraged pro-union supporters to get behind the Tory candidate, Alexander Burnett.
She said: “It is clear that the Scottish Conservatives are the only pro-UK party which is going to put on votes in this election, and I hope put on seats.
“If you are a pro-UK person, if you fought head, heart, body and soul to keep Scotland in the UK, then there is only one party that is on the rise, standing up for the UK and not offering any deals with other parties.”
Ms Davidson added: “I think we are going to do better, we are going to get pretty close to 500,000 votes this time.”
The Scottish Conservative leader yesterday continued a trend of attention grabbing picture opportunities during the general election campaign with a trip from Aviemore to Boat of Garten on the Strathspey railway.
Today, she will give her final speech of the election campaign at Dynamic Earth, next to the Scottish Parliament building in Edinburgh.
Ms Davidson will say that every vote cast for the Conservatives will help keep the UK together.
Meanwhile, Tory campaigners seized on moves by the bookmakers to reduce the odds on Mr Burnett in West Aberdeenshire and Kincardine from 9-2 to 10-1, which they said backed the argument that it is now a two-horse race with the SNP.
Liberal Democrats are insisting that the strong personal vote for Sir Robert is holding up, however.
The split in the unionist vote could well leave the door open for SNP candidate Stuart Donaldson.
Constituency polling carried out by Tory peer Lord Ashcroft previously reflected this, putting the Nationalists in front.