Party leaders have made their final pitches to Scots in the hours before the snap summer general election.

Voters have been told that many constituency races are in the balance ahead of polls opening at 07:00 on Thursday.

First Minister John Swinney told voters that while the result of the election in England is a “foregone conclusion”, the vote in Scotland is “on a knife edge”.

“There are seats that could be decided by only a handful of votes,” he said.

Speaking at a campaign event earlier, the SNP leader said he was confident his party would win a majority of seats in Scotland.

He added: “The election is well and truly over and done with south of the border. The issue for Scotland is who is going to protect Scotland’s interests in the next Westminster parliament and people know they can rely on the SNP to do exactly that.”

The SNP returned 48 MPs at the 2019 election, with Labour holding on to just one seat, but Sir Keir Starmer’s party has high hopes of a revival north of the border.

Scottish Labour leader Anas Sarwar, speaking alongside UK party chief Sir Keir Starmer in East Kilbride, told supporters: “Scotland faces a choice. Five more years of Rishi Sunak and the Tories, or change with Labour and Keir Starmer.”

“Five more years of chaos and division or the journey of change that gets opportunity back for so many Scots.”

Sir Keir said: “I want a Labour government to have Scotland at its heart. The route to a Labour government runs through Scotland, has always run through Scotland.”

He told supporters he did not want Scotland to send a “message” to Westminster, adding: ”I want Scotland to send a government.”

Meanwhile, Scottish Conservative leader Douglas Ross said it was between his party and the SNP in several key seats.

He urged voters to unite behind his party to “end the nationalist obsession with independence”.

Mr Ross, who is standing down as Scottish Tory leader after the election, said: “Many of these contests are still on a knife-edge.

“It could come down to just a few votes, which is why people need to get out, support the Scottish Conservatives and send that resounding message to the SNP that they have failed Scotland and our public services for the last 17 years because their eye has been off the ball.”

Scottish Liberal Democrat Alex Cole-Hamilton also warned some constituencies were on a knife-edge.

He said there were “good reasons” for voters to back his party, adding: “Whether that’s because we’re prioritising what matters to people, like access to local healthcare, schools, getting the sewage out of our rivers and repairing our broken relationship with Europe.”

There are 4,081,585 registered voters in Scotland. About a quarter of them – 998,863 – are postal voters.

Yet concerns have been raised about Scots receiving their postal ballots in time.

The 4 July election falls in the first full week of the school summer holidays in most parts of Scotland, with delays in receiving postal votes resulting in some Scots being left without a vote due to pre-planned overseas holidays.

In a letter to Prime Minister Rishi Sunak, John Swinney said the issues had been caused by a combination of Mr Sunak’s decision to hold the vote on an “unsuitable date”, and the timetable for elections leaving “little room” to address issues.

Mr Sunak’s official spokesman told reporters the prime minister did not share Mr Swinney’s concerns.

He added that the UK government was working with the Electoral Commission, elections officials and the Royal Mail to resolve any issues.

UK Postal Affairs Minister Kevin Hollinrake is said to be “urgently investigating” the issue, but Royal Mail has rejected claims there is a backlog, saying the service is “not complacent”.