SCOTS could be forced to hand over their British passports and be barred from holding dual nationality with the UK after independence, Home Secretary Theresa May has signalled.

Her comments will be a blow to the Scottish Government, which has reassured voters they will be able to hold shared or dual citizenship.

Mrs May's comments came in response to a remark by SNP MP Pete Wishart, that "of course after an independent Scotland it will be possible to keep a UK passport".

In reply, the Conservative minister told him to think "very carefully about what he has said," and added: "Decisions on UK citizenship remain with the UK Government, but if the vote in the referendum is for a separatist vote then Scotland will become a separate state – it will not be part of the UK."

A Home Office source added: "What the Scottish Government cannot promise is that, if Scotland became independent, people would retain the option of dual Scottish and UK nationality – decisions on UK citizenship are for the UK Government."

The No campaign, Better Together, said the only way to guarantee Scots could keep their British passports was to vote against separation next year.

A spokesperson for Yes Scotland said: "We anticipate an inclusive definition of citizenship, and that dual citizenship would be offered in acknowledgement of the close ties across the UK."

Mr Wishart said he was surprised by Mrs May's comments, adding: "This is in the gift of the UK Government but I would hope the rest of the UK Government would be reasonable in engaging in these discussions".

A Scottish Government spokesman said: "An independent Scotland will manage citizenship in a way that effectively meets our nation's economic, social and demographic priorities and needs, and a White Paper setting out our detailed proposals on citizenship will be published in the autumn."