THE Scottish Government's plan for an independent Scotland to be fast-tracked into the EU is unlawful, a senior former Brussels lawyer has warned.

Jean-Claude Piris, the director general of the EU Council's legal services from 1988 to 2010, said an independent Scotland would have to apply for membership in the usual way, under rules laid down in the Lisbon Treaty.

The process would also require an independent Scotland's membership of the EU to be ratified by referendums in a number of member states, including France and Denmark, he warned.

The SNP claim an independent Scotland's membership would be fast-tracked under Article 48 of the Treaty.

The proposal - described by the UK Government as a "novel interpretation of EU law" - would avoid a standard, potentially lengthy application under Article 49.

But in a submission to the Scottish Parliament's European and external relations committee, Mr Piris warned: "It would not be legally correct to try and use Article 48 of the Treaty on European Union for the admission of Scotland as a member of the EU.

"Only Article 49 of the same Treaty would provide for a suitable legal route."

He said entry must be approved by the main EU institutions - the European Commission, Council and Parliament - plus individual member states.

He added: "In the case of France the constitution provides that in principle the ratification of an admission treaty must be authorised by a referendum."

Speaking at First Minister's Questions, Scots Tory leader Ruth Davidson accused Alex Salmond of "misleading" the public over EU membership though she was ordered to withdraw the comment by Presiding Officer Trica Marwick, who ruled it "unparliamentary language".

Mr Salmond insisted the Scottish Government's position on EU membership was supported by the new adviser to the pro-UK Better Together campaign, Professor Jim Gallagher.

He quoted a blog by Mr Gallagher - revealed in Wednesday's Herald- in which he said "accelerated" accession talks would be "pretty likely".

He told MSPs: "If Prof Jim Gallagher is saying that, the guru of the Better Together campaign, can't we just accept the burden of opinion favours the position adopted by the Government?"

Laura Cram, professor of European politics at Edinburgh University, said an independent Scotland would not be ejected from the EU even if membership talks dragged on.