A ban on EU migrants claiming benefits from the moment they arrive in the UK is to be fast-tracked amid fears of an influx of Bulgarians and Romanians in the new year.
The measure will be rushed through Parliament in time for the January 1 deadline when Bulgarian and Romanian nationals gain full rights to live and work in Britain.
Currently EU migrants are entitled to claim benefits as soon as they enter the UK.
However, last month David Cameron announced the three-month delay as one of a number of measures aimed at restricting so-called "benefit tourism".
The ban will come into effect from the first day of the new year and from that point, with a few exceptions, all migrants from other EU states will have to wait three months before claiming out of work benefit.
After six months on £71-a-week Jobseekers Allowance, only those who can provide evidence that they have a genuine chance of finding work will be allowed to continue claiming.
The European Commission warned that it will be checking the legality of the Government's rules on how long EU jobseekers must wait to claim benefits.
Jonathan Todd, spokesman for EU Employment Commissioner Laszlo Andor, said: "For the moment it is too early to say whether the new rules are compliant.
"The UK is obliged to notify changes in social security rules affecting other EU nationals to the Commission and to other member states. It should do so at the meeting of member states' social security co-ordinators taking place in Vilnius today and tomorrow.
He went on: "In any case, EU nationals going to the UK to look for work are entitled to jobseekers' allowance from their home country for up to three months, and some countries make the allowance available for up to six months."
But Mr Cameron said: "The steps that we are taking, including the announcement today, that people coming to the UK should not be able to claim benefits for the first three months - we are taking these steps on the basis of legal advice and looking very carefully at what other countries in the EU do.
"I want to do everything possible to make sure the right of free movement is not abused."
Work and Pensions Secretary Iain Duncan Smith suggested there were more measures to come and that migrants should not expect to claim benefits until they have paid sufficient taxes.
He told Sky News: "In essence, if people travel to another country, in due course, we want to be able to tighten it up so that you remain the responsibility of your home nation until you have demonstrated that you are responsible, you have been earning, you pay taxes and therefore you become eligible for benefits."
The Government's own figures for 2011/12 show that only 7% of those claiming Jobseeker's Allowance, Employment and Support Allowance, Incapacity Benefit or Income Support were foreigners and only 31% of those were from within the EU.
Labour on Wednesday accused Mr Cameron of a "chaotic" approach to bringing in the new measures.
Shadow home secretary Yvette Cooper said: "Labour called for these benefit restrictions nine months ago. Yet David Cameron has left it until the very last minute to squeeze this change in."
Other measures in Mr Cameron's package include stopping housing benefit claims for EU jobseekers; toughening the "habitual residence" test for claimants ; imposing a 12-month re-entry ban for people who have been removed for begging or sleeping rough; and increasing fines for businesses found not to be paying the national minimum wage.
:: Watch Sky News live on television, on Sky channel 501, Virgin Media channel 602 and Freeview channel 82.