The Home Office is planning for a potentially large increase in immigrants from Greece and other European Union nations as a result of the crisis in the euro, Theresa May has revealed.

The Home Secretary admitted "work is ongoing" to deal with large movements of people in the event of the break-up of the single currency.

Should Greece leave the euro and go bankrupt, millions of people could lose their jobs and may look for work abroad, with Britain, as a non-eurozone country, being seen as an attractive alternative.

Mrs May did not indicate the sort of response that was under consideration, and said while there was no evidence of increased migration at present, it was "difficult to say how it is going to develop in coming weeks".

Prime Minister David Cameron cast doubt on the future of the euro last week when he warned the eurozone that it "either has to make up or it is looking at a potential break-up".

"That's the choice they have to make and it is a choice they can't long put off," he told the Commons.