The UK Independence Party (UKIP) has launched its election campaign with a vow to make Scottish MPs work part-time between Holyrood and Westminster.
UKIP has questioned the role of Scottish MPs
Under its proposals, Scotland's 59 MPs would only be allowed to sit for two days a week in London and only vote on UK and not English legislation.
For the rest of the time they would sit at Holyrood, along with an equal number of MSPs, half the current tally.
The party is fielding 20 candidates in Scotland.
Bryan McCormack, the UKIP candidate for Ayr, Carrick and Cumnock, said quitting Europe would free up money to improve Scotland's economy.
"As a result of coming out of Europe, we won't have to spend £30m a day, £12bn every year," he said.
"When you factor in the £18bn worth of savings to business from not having to comply with needless regulations, you can then say to people 'we can put your pension up by £25 a week and we can cut your council tax in half'."
Maintaining an established strategy of putting the economy at the heart of its campaign, Labour has claimed that of all Scotland's European competitors, only Denmark is closer to full employment than Scotland.
Scottish Secretary Alistair Darling said Labour's plans were geared towards economic stability and low inflation.
Addressing the Scottish Council for Development and Industry in Edinburgh, he said: "In the last seven or eight years we have been determined that whatever else we do, we will not put at risk that stability we believe is so essential to the future of our economy.
"Our economy has grown for a long period now, although in Scotland our growth needs to be stronger.
Alistair Darling praised Labour's economy drive
"We've had the longest single period of growth since records began and that's very important for the country and for industry, to enable you to plan ahead and take decisions for the long-term."
Meanwhile, Scottish Lib Dem leader Jim Wallace visited the sand dunes of a Highland beach to stress the party's commitment to the environment.
Mr Wallace said his party would focus on four issues - climate change, cleaner transport, increased support for renewable energy and not replacing nuclear power stations.
He said his party would deliver a "better environment" and ensure that Kyoto targets were met in Scotland.
He said: "This will have the greatest potential impact on reducing climate change emissions."
On transport, he outlined how the party planned to reform vehicle excise duty, cut tax on cleaner cars and increase it on those polluting more.
The Lib Dems would also help the growth of the bio-fuel industry in Scotland and replace petrol duties and vehicle excise duty with a national road user charging scheme based on location, congestion and pollution.
"Paying more for journeys at peak hours in highly congested areas, paying less to drive in rural areas at off-peak times," said Mr Wallace.
"This will increase the attractiveness of public transport in urban areas and cut the cost of transport in rural areas."
He also said they would ensure a review of the electricity transmission charging to help Scotland reach its green energy target.
However, the party ran into immediate fire from the Greens, who are fielding about 20 candidates in Scotland.
They accused the Lib Dems of abandoning their principles and Green MSP Patrick Harvie pointed to the party's record in Scotland on GM crops and the M74 motorway extension.
He said: "The Lib Dems in government have been the biggest disappointment of devolution, talking a good game but prepared to make any compromise to keep their ministerial Mondeos.
"Any green thread their policies may have had in opposition will be buried under the tarmac of the M74 extension."
The Tories turned their guns on Tony Blair personally, accusing him of stabbing Scottish troops in the back while they fought in Iraq.
Peter Duncan accused Labour of stabbing soldiers in the back
Conservative candidate Peter Duncan said: "In one of the most treacherous acts in recent political history, Mr Blair announced that the Scottish regiments would be abolished at the same time as the very regiments he was scrapping were fighting in Iraq.
"Mr Blair sent our troops to war in Iraq. They did a thoroughly professional job in liberating Iraq and giving its people the chance of a better life, and they did Britain proud.
"Like the vast majority of people in this country Conservatives were full of admiration for their efforts and are eternally grateful for their sacrifice.
"It's just a shame that Tony Blair doesn't seem to be so impressed with the Scottish regiments. It simply makes your blood boil."
He added that the move by Mr Blair had put trust in the in government is at an all time low.
Elsewhere, the Scottish National Party launched its "people's manifesto" in Glasgow which will focus on improving the lives of voters in Scotland.