Prime Minister David Cameron was on an early morning visit to Scotland as the campaign north of the border picked up after the Easter holidays.
The leader of the Tories plans to visit all four parts of the UK on Tuesday.
Elsewhere, First Minister and SNP leader Nicola Sturgeon spoke about policies to reduce child poverty.
Scottish Labour leader Jim Murphy has been talking about opportunities for young people while the Liberal Democrat theme is fairness in the tax system.
There are 30 days left until voters go to the polls.
Mr Cameron, who had breakfast with wife Samantha at the Edinburgh HQ of Scottish Widows, said: "Today, I am travelling to all four nations of our United Kingdom, to all four corners of our country, with one simple message: we have one month to save our economy from the disaster of an Ed Miliband government.
"We have one month to save Britain from his mountain of debt; one month to save Britain from his punitive taxes; one month to save Britain, and British families, from his anti-business and anti-aspiration agenda.
"These past five years we have got Britain back on its feet. All four nations are growing; jobs are being created the country over; taxes are coming down; the deficit has been halved as a share of our economy; and more families can look forward to a brighter future."
Children and young people
Liberal Democrat deputy leader Sir Malcolm Bruce has been campaigning in Aberdeenshire.
While speaking to staff at a local hotel, he highlighted his party's record in government on cutting taxes for workers.
He said: "We want to cut taxes for working people - people on low and middle incomes. Not only do we want to do it, we've done it in government against the Conservatives.
"We've had to fight it through and we've delivered it when they said it couldn't be done. And we can go on doing it and we have shown how we can fund it."
Setting out her concerns, Ms Sturgeon told an audience in West Lothian: "Years of Westminster austerity have harmed the poorest ten per cent of households harder than anyone else - hitting families with children hard. That is only set to continue with all of the Westminster parties signed up to a further £30 billion of austerity cuts and the Tories planning to slash welfare spending by £12bn.
"The absolute last people who should be paying the price of austerity cuts are children, yet that is precisely what is happening under the plans of all of the Westminster establishment parties.
"The UK Government's current plans will see one million additional children across the UK grow up in poverty, 100,000 of whom will be in Scotland."
Speaking to young activists in Glasgow, Mr Murphy spoke about opportunities for the young, confirming that this will be a theme in his contributions to this evening's STV leaders' debate.
He said: ""I am proud that Scotland invests in those young people who continue to learn after school or who are lucky enough to get an apprenticeship.
"But those who don't do either can feel abandoned, and their optimism of youth can be quickly ground down into hopelessness. Our future fund gives these young Scots a reason for optimism, it gives them hope for the future, and is an investment in our country's future."
"That is why I am looking forward to the debate. It is a chance for Labour to share with the Scottish people our better plan for a fairer Scotland."