The Scottish National Party has marked the official launch of its campaign with an attack on Labour over its funding of public services.

The SNP argued that over the next two years £7.7 billion pounds will be transferred from Scotland to the Treasury in London, a claim that was swiftly disputed by other parties.

Launching his party's push towards polling day, SNP leader John Swinney said: "This election campaign will be about who can be trusted to stand for Scotland. SNP votes and SNP MPs will work to complete the powers of the Scottish parliament with independence, and promote the Scottish interest."

Referring to the Barnett formula for allocating spending between the UK's regions, Swinney also accused Labour of not spending enough north of the border.

"New Labour - following on from the old Tories - are cutting Scotland's share of spending on public services," he said.

Hitting back for Labour, George Foulkes attacked the SNP as the party with "Still No Policies" and said a vote for them would only help the Conservatives.

"We're now into day four of the general election campaign and the nationalists have come up with nothing new for the people of Scotland," said Foulkes.

"It's hardly surprising their campaign launch was nothing more than a glorified photocall. The side they are fielding is not so much a second team, more a Sunday league side," he added.