Scotland's independent membership of the EU could be blocked by eastern European countries seeking greater farm subsidies and other states with internal secessionist movements, according to UK Europe Minister David Lidington.

If Scotland votes for independence it will have to seek the unanimous approval of EU member states to rejoin, Mr Lidington told media at the Scottish Parliament today.

The Scottish Government insists that it will negotiate a cut-price membership of the EU, with opt-outs from the euro and passport-free travel zone, from within the union ahead of independence day in 2016.

But Mr Lidington said the overwhelming weight of opinion and historical precedent points to Scotland becoming a completely new state.

EC president Jose Manuel Barroso has said "an independent state has to apply to European membership according to the rules", while Nato has said Scotland "would not be a party to the North Atlantic Treaty" and would have to reapply.

If Scotland faces normal accession, Spanish European Parliament vice-president Alejo Vidal-Quadras has said Spain and France "will surely not" accept Scotland to quell Basque separatism, citing Spain's continuing opposition to Kosovo.

The SNP's nationalist allies in Catalonia and Flanders have also advised Spain may try "unsuccessfully" to block Scotland's membership, and that negotiating an "al a carte" membership of the EU would "make life more difficult".

Now Mr Lindington has suggested Scotland could face vetoes from Poland, Romania and Croatia as well.

"It's not just Spain where the debate about autonomy or even separation is a part of politics," he said.

"Five EU member states still refuse to recognise Kosovo.

"For Scotland to become a member of the EU in its own right it has to have the unanimous consent of every other member state, not just to the principle of membership but to all the terms of that membership.

"Just one dissenting vote is enough to block accession, or to block any stage of accession, so if one country felt strongly that an independent Scotland should be required to accept the euro then they would have the power of veto.

"On agricultural policy, the new member states of eastern and central Europe would have to accept a situation now where they don't get their full notional entitlement to agricultural support.

"It's only slowly being transferred to the big recipients in western Europe, so Scotland applying to join the EU would presumably either have to accept that lower level of agricultural support to be in line with all of the other member states, or all of the other eastern European countries would have to agree to Scotland leapfrogging them to get the full entitlement before they got it.

"Would Poland, Romania, Croatia be happy with that? I don't know but this is another question which it seems to me has not been properly addressed."

Mr Lidington refused to confirm or deny whether the UK Government had asked its law officers for advice on international relations in the event of Scottish independence.

This contrasts with the Scottish Government who were told by the Scottish Information Commissioner that the public interest lay in disclosing whether law officer advice had been commissioned, although it has subsequently decided to withhold the advice from publication.

Mr Lidington said: "Formal legal advice from the law officers is something that we don't disclose.

"Our case has always been that you don't have to ask what the UK law officers think.

"The overwhelming weight of published legal opinion by academic lawyers, the weight of international precedent - if you look at how splits in other countries have been treated such as India, Pakistan, Bangladesh and the UK and Ireland - all point towards the remaining UK being the continuing state and Scotland seeking fresh membership of the various international organisations.

"That's a point that European Commission president Barroso has publicly supported now, it's a point that Nato has formally said would be the case of membership."

A Scottish Government spokeswoman said: "The future of Scotland is a democratic decision for the people of Scotland, not for politicians from other EU countries.

"Scotland has been an integral part of the EU for four decades, and an independent Scotland will continue in EU membership.

"Ministers have always been clear - including in the Government's published documents - that there will be negotiation on the specific terms of our continued membership, but that these discussions will take place from within the EU.

"In the transition period immediately after a vote for independence in 2014, Scotland will still be part of the UK, so by definition will still be part of the EU while these negotiations take place. As such, Scotland would enter discussions with our share of the existing relationship between the UK and the EU, including existing opt-outs, as the basis for agreement.

"Scotland is already part of the territory of the EU and the people of Scotland are citizens of the EU - and, as legal, constitutional and European experts have confirmed, there is no mechanism for this status being removed. The Scottish Government's proposed 18-month transition timescale to independence has been described as 'realistic' by one of the UK Government's own chosen experts on the subject.

"An independent Scotland will keep the pound, and a shared Sterling area will be in the overwhelming economic interests of the rest of the UK. There is no mechanism to make any EU member state join the Euro, as the case of Sweden proves. And Scotland will remain part of the Common Travel Area with the UK and Ireland, an arrangement which long predates Schengen.

"And in terms of agriculture, under the terms of the most recent Common Agricultural Policy (CAP) negotiations, an independent Scotland would have received an extra one billion euros of support between 2014 and 2020 than Scotland's farmers will get under the Westminster system."