The UK government should stop "scaremongering" over issues such as border controls, Scotland's first minister has insisted.

Alex Salmond's comments came after the coalition government's Europe minister claimed that Scotland may have to establish passport controls at the English border if it voted for independence.

On a visit to the Scottish Parlianment on Monday to discuss developments in the eurozone with MSPs, David Lidington said Scotland would not necessarily inherit the UK's opt-out of the Schengen Agreement which permits freedom of movement around most of Europe.

The opt-out means EU citizens are still subject to passport checks at UK borders.

Speaking in a post-committee briefing, he said opt-outs like Schengen, and also of the euro currency, "require not just a bilateral agreement between the UK and an independent Scotland, it would require the agreement of all of the other member states as well".

He said: "The fact that the UK has an opt-out from Schengen means that we are able to maintain the border controls that you don't have on the borders between Schengen countries.

"Logically, if Scotland were in Schengen, every Schengen country has to dismantle border checks with other Schengen countries, and have border checks with other EU states that are outside Schengen.

"That is why, for example, if I fly to Munich from London I have to go through a passport check before I can transit to a plane connecting to Poland.

"So there's a logic in the way that Schengen is organised, and that is a clear problem that Scotland would have to face up to."

But a spokesman for Salmond responded by saying: "It is in the interests of the UK Government to stop scaremongering on these issues because their silly claims are rebounding back on them, just as the attacks on an independent Scotland's credit rating have backfired on the Chancellor.

"All of these tired old scare stories are demonstrably untrue. They are insulting to Scotland and the only effect they are having is to boost support for independence.

"As legal, constitutional and European experts have confirmed, the reality is that Scotland is part of the territory of the European Union and the people of Scotland are citizens of the EU. There is no provision for either of these circumstances to change upon independence, and the rest of the UK will be in exactly the same position.

"We will both be successor states, with exactly the same status within the EU, as the AFP news agency reported only last week.

"Therefore, for example, the cast-iron position is that an independent Scotland will continue to use the pound. The Scottish Secretary in the UK Government has said that Scotland can continue to use sterling, so the Westminster coalition is totally incoherent.

"The lesson for UK politicians is to be careful what they say about Scotland because the same attacks apply to them. The anti-independence parties should adopt a more positive and constructive approach."

However, Lidington's comments were gfiven some backing by Scottish Liberal Democrat leader Willie Rennie MSP, who said: "Passport controls between England and Scotland would have a significant impact on the ease of travel between our two nations. This would have an impact on business and personal relations.

"The SNP may hysterically dismiss these concerns but they need to provide us with a guarantee backed by evidence that this will never happen. Only then will we believe their assertions."