First Minister Nicola Sturgeon has branded Boris Johnson the "greatest danger to Scotland of any Tory Prime Minister in modern times".
In an open letter to voters ahead of polls opening on Thursday, Ms Sturgeon urged people to support her party.
In response, the Scottish Tories described the First Minister as "the most divisive person in UK politics".
Mr Johnson's plans for the NHS, workers' rights, the environment, child poverty and Brexit were in the firing line in the letter - which ended with the First Minister claiming Scotland "cannot afford five more years of Boris Johnson".
READ MORE: Scotland Leaders Debate: Sturgeon pressed on IndyRef2 plans during TV clash
The letter said: "I've been in politics for a good number of years now.
"I saw the damage a previous Tory Prime Minister unleashed on communities like mine in the west of Scotland.
"I resolved then to get involved, to do whatever I could to make a difference, and that's what I'm asking you to do on Thursday.
"We've all seen the impact on ordinary people caused by Tory Governments that we didn't elect and Boris Johnson, without question, represents the greatest danger to Scotland of any Tory Prime Minister in modern times."
The First Minister added: "His hard-line Brexit policy would cost jobs and hit living standards - and will be carried out against the wishes of the majority of people who live here.
"He is a threat to the NHS. He will put many more children into poverty. He will rob young people in Scotland of rights they currently enjoy.
"He's a danger to workers' rights and environmental standards. And he will trample all over the Scottish Parliament if it gets in his way.
"Much of what we hold dear in Scotland will be cast aside as Boris Johnson reshapes the UK in his own right-wing Brexiteer image."
The First Minister ended her letter by asking for voters' support, saying more SNP MPs in Westminster will help create "the better Scotland we know is possible".
At a campaign event in East Renfrewshire, the First Minister told the PA news agency this election offered a chance for voters to "come together".
She said: "If people don't want to wake up to five years of a majority Boris Johnson Government with Scotland being taken out of the EU against our will, with the NHS on the line in a Trump trade deal, with child poverty rising ... then we need to come out on Thursday to vote to stop that."
Ms Sturgeon said the SNP were the main challengers in Scotland, branding Labour "too weak".
READ MORE: New poll shows Boris Johnson can 'no longer be sure' of Conservative majority
Tory MSP Annie Wells accused the First Minister of "scaremongering", saying: "This is desperate, negative stuff from a First Minister who appears to be panicking as this election campaign reaches its conclusion".
"She has nothing positive to offer so all she can do is scaremonger.
"The reality is that the most divisive person in UK politics right now is Nicola Sturgeon because, as she has herself made clear, she wants to take us back to another independence referendum within the next 12 months.
"There is only one way to stop that on Thursday - and only one way to get the country moving forward - and that is to vote Scottish Conservative and Unionist."
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