Migrants will only be able to claim benefits if they pass a series of tough new tests, including a check on their fluency in English, the Government is announcing today.

The moves, which will come into force a fortnight ahead of the removal of transitional controls on Romanian and Bulgarian workers, are designed to send a strong deterrent message to potential “benefit tourists”.

From next Wednesday foreign-born benefit claimants will face more questions in lengthier interviews. The rules apply to all overseas nationals, regardless of whether or not they are from the European Union, and to Britons returning after living abroad.

Download the new Independent Premium app Sharing the full story, not just the headlines

For the first time claimants will be challenged to demonstrate their proficiency in English and to prove they were genuinely looking for work before they came to this country.

JobCentre Plus staff, who will conduct the interviews, will have a secret list of 100 questions which they can be tailored to individual interviewees by an “intelligent IT system”.

They could be asked to provide details of family ties abroad, details of their dependants and proof they have a permanent British address.

The tests, described by ministers as “more robust”, are currently being introduced in England, Wales and Scotland and will be fully in place within five days.

They will exacerbate an existing dispute between the Government and the European Commission, which has condemned Britain’s existing “habitual residence test” for benefit claimants as discriminatory. Instead of backing off, Iain Duncan Smith, the Work and Pensions Secretary, is raising the hurdles claimants have to clear to qualify for income-related benefits, such as jobseekers’ allowance.

He said: “It is vitally important we have strict rules in place to protect the integrity of our benefits system.

“The British public are rightly concerned that migrants should contribute to this country and not be drawn here by the attractiveness of our benefits system and we are taking action to ensure that is the case.”

Habitual residence tests were first introduced in 1994 and have undergone various revisions since then.

The European Commission believes rules limiting the rights of EU nationals to receive income-related benefits are discriminatory and is taking Britain to court. Mr Duncan Smith’s move to tighten the tests will be seen as provocative by Brussels but he insists the UK is working within EU law.

The Government said the latest research showed that almost 400,000 overseas nationals were claiming working age benefits in February, an increase of around 110,000 since 2008.