An opinion from the European Union's top policy maker that newly independent countries would not inherit the EU treaties of the countries from which they separate is "without foundation", according to a senior Scottish minister.

Scottish Finance Secretary John Swinney gave evidence to the House of Lords Economic Affairs Committee, challenging the opinion of European Commission president Jose Manuel Barroso, which has implications for Scottish independence.

In a letter to the committee, Mr Barroso wrote that "if a territory of a member state would cease to be a part of that state because it were to become a new independent state, the treaties would no longer apply to that territory".

Mr Swinney told the committee that the statement had no basis in EU treaties and said Mr Barroso may have "inadvertently created a specificity about it".

But Mr Swinney was accused of acting like a "scoundrel" for making "irrelevant" and "implausible" arguments to knock down what many members of the committee regard as an authoritative statement from the EC.

Mr Swinney said: "Essentially, I don't agree with the contents of President Barroso's letter for the reason that I do not see the basis within the treaties upon which that remark is founded."