SCOTLAND would stay in the EU after independence because much of the continent would face a "legal nightmare" if it did not, according to a leading Brussels think tank.

The European Policy Centre reckons member states would accept the SNP's proposed but controversial fast-track re-entry to avoid their citizens and firms losing their rights in the newly created state.

Its expert Graham Avery - who has come under fire from pro-UK politicians for branding Westminster's stance on the issue as "absurd" - suggested the realpolitik was such that membership or a temporary special relationship was assured. Prof Avery said: "From a practical point of view, no member state has a material interest in Scotland remaining outside the EU, even for a short time.

"This would deprive the EU of Scotland's budgetary contribution, fisheries resources. Scotland outside the EU, and not applying EU rules, would be a legal nightmare for EU member states, whose citizens and enterprises would lose their rights in Scotland.

"No member state, particularly not the rest of the UK, would have an interest in creating such an anomaly."

Prof Avery dismissed comparisons with Kosovo made by Jose Manuel Barroso earlier this year when the EU President said it would be "extremely difficult, if not impossible" for Scotland to rejoin the bloc.

The expert - an honorary director-general of the European Commission - also said he expected the EU to use Article 48 of the constitution - the amendment of treaties to allow Scotland to join upon independence. But he stressed that the bloc would have to assuage opinion in Spain and elsewhere by "reaffirming its respect for the constitutional arrangements of member states".

SNP MEP Alyn Smith said: "This report debunks much of the nonsense peddled on Scotland and the EU by people who should know better. The European Policy Centre is as serious as it gets in Brussels."

Prof Avery has long argued that the EU would neither want nor be able to impose the euro or the Schengen travel area on Scotland. However, he warned of "sensitive" renegotiation of Scotland's share of the UK's rebate.

A spokesman for Better Together disagreed: "As part of the UK we get special deals in the EU. What Alex Salmond needs to be honest about is what would happen to our opt-outs on the Euro and the no borders immigration scheme, as well as what would happen to our rebate. Telling Scots that everything will be alright on the night simply isn't credible."