Berlin: Harsher measures should be taken against asylum seekers if they take a holiday in their country of origin, Chancellor Angela Merkel said in an interview on Sunday, in which she also said she had no regrets over her open-door refugee policy.

"Taking holidays in the country in which you are being persecuted is not on," the German leader said in an interview with Welt am Sonntag, adding that it could be a reason to re-examine an asylum case.

While there is no official data on asylum seekers returning to their home countries on "holiday", the issue has been the focus of media reports in Germany.

Newspaper Die Welt first reported last year that it had uncovered cases of recognised asylum seekers who travelled to countries such as Syria and Afghanistan for a short time. Martin Retsch, from the UN Refugee Agency, said the practice was not "widespread". The issue is, however, indicative of the tensions that have built in Germany.

Mrs Merkel said she has no regrets over her refugee policy, which saw Germany controversially open its doors to hundreds of thousands of refugees two years ago, despite the deep rifts the decision caused in her party.

"I would make all of the important decisions of 2015 the same way again", she said in the interview.

Four weeks ahead of the German election, an Emnid opinion poll suggested Mrs Merkel's refugee policy was not likely to lose her the election, putting her Christian Democratic Union (CDU) 15 points ahead of the Social Democrats (SPD).

However, 46 per cent of voters have yet to make up their minds, according to a survey for Frankfurter Allgemeine Zeitung newspaper.

Martin Schulz, Mrs Merkel's main challenger, stepped up his attacks yesterday, labelling the Chancellor "aloof" and "out of touch".

Telegraph, London