SNP leader John Swinney has called on political parties north of the border to form a new coalition to campaign against English top-up tuition fees.

Scotland's shadow first minister said that the differential university fees pose a threat to Scottish higher education.

Nationalists MPs at Westminster are to break their promise not to vote on English legislation over the issue.

And Swinney will challenge other parties to protect Scotland's universities by opposing the Labour government's plans.

Scotland opted for a graduate tax system after the devolution settlement in 1999 instead of England's up front tuition fees.

The SNP believes that funding streams to Scottish higher education will be cut because of plans to raise the maximum fees universities can charge in England.

In a speech at Dundee University Swinney argued that the Barnett formula - which decides Scottish funding levels from national tax revenues - will be skewed against Scotland as the fee income will not count as tax.

"That means that there will be no extra spending generated for Scotland if that spending is coming out with the Barnett Formula," he told the BBC on Friday.

"That poses a real threat to Scottish higher education because it puts us at a competitive disadvantage to institutions south of the border.

"That will affect staff, research and development and the whole effectiveness of the higher education sector in Scotland.

"All political parties recognise top-up fees to be bad for Scotland and we should unite to oppose them."