Nicola Sturgeon has said the Tory government is short-changing young people with its "discriminatory" minimum wage policy.
She joined young SNP activists on the campaign trail in Kirkintilloch, East Dunbartonshire, on Saturday, saying the party's MPs will demand an end to the "rip-off" of workers aged under 25.
The national minimum wage is currently set at £8.21 for employees over 25.
It reduces in line with age, with under-18s receiving £4.35 per hour.
The first minister said: "Even before Brexit takes away so many opportunities for our young people, the Tories are already short-changing them with their discriminatory minimum wage policy.
"Two people working alongside each other, doing the same job, could be paid entirely different wages, just because of their age. That is simply not fair.
"Around 89,000 young people in Scotland would be better off and able to get a better start in their working lives if they were simply paid the same legal living wage as their older colleagues."
Ms Sturgeon was campaigning in the constituency of Liberal Democrat leader Jo Swinson, while the Lib Dems Scottish leader Willie Rennie appealed to voters in North East Fife, the most marginal seat in the UK.
The SNP held the constituency by just two votes ahead of the Liberal Democrats in the 2017 election.
Mr Rennie said: "Only the Scottish Liberal Democrats can take seats from the SNP at this election.
"We need to learn the lessons of Brexit, not repeat the mistakes with independence. That's why I am directly appealing to everyone who wants to end the constitutional division to come with us.
He said: "There is no doubt momentum is with the Liberal Democrats. We are gaining support right across the country. We are best placed to challenge the SNP in Scotland."
Richard Leonard campaigned in Glasgow on Saturday, with the Scottish Labour leader outlining his party's "radical" 10-point plan to tackle child poverty.
The plan includes measures to scrap Universal Credit and replace it with a new social security system, and introduce a £10 per hour living wage.
Labour say they will build 120,000 social homes over the next decade and introduce free meals at weekends and holidays for school pupils across Scotland.
Mr Leonard said: "A combination of callous Tory welfare reform and SNP timidity has allowed the unforgivable to happen - child poverty in Scotland is rising."
Meanwhile, Scottish Tory leader Jackson Carlaw discussed his party's pledges at a campaign event in Clarkston, East Renfrewshire.
He said: "This morning, thanks to a UK government manifesto commitment, there is an additional £200m available for Scotland's NHS.
"We want to see that directed entirely to GP services. Contrast that with Nicola Sturgeon's plans for a second independence referendum which will create a black hole, taking a scalpel to Scotland's NHS, putting the welfare of people in Scotland at risk."