LONDON (Reuters) - British Prime Minister David Cameron said on Wednesday he was rushing out regulations to stop EU migrants being able to claim welfare benefits as soon as they arrive amid fears there will be an influx of Romanian and Bulgarian workers after January 1.
Cameron is under pressure to act on the issue, with his Conservative party trailing in opinion polls ahead of a 2015 election and surveys showing most Britons don't want the labour market to be further opened up to east European workers.
Anxious not to be outflanked by the anti-immigration UK Independence Party (UKIP), he has said he shares public concerns about restrictions on Romanians and Bulgarians working in Britain being lifted at the end of this year.
On Wednesday, he said he was bringing forward to January 1 a previously announced measure that will force European Union migrants to wait three months before they can apply for welfare benefits.
A senior government source told Reuters that Cameron had originally envisaged the measure taking effect around the middle of next year.
Cameron said in a statement: "Accelerating the start of these new restrictions will make the UK a less attractive place for EU migrants who want to come here and live off the state.
"I want to send the clear message that whilst Britain is very much open for business, we will not welcome people who don't want to contribute."
The European Commission, which has in the past accused Cameron of indulging in unhelpful rhetoric on immigration, said it would study the measure to ensure it complied with EU law.
EU job seekers are entitled to claim welfare benefits from their home country for the first three months anyway, a commission spokesman in Brussels told reporters.
"There is absolutely no evidence that EU nationals go to the UK in order to claim benefits or that there is widespread or systemic abuse by EU nationals of other countries' welfare systems," the spokesman told a daily news briefing.
Cameron told parliament on Wednesday he had taken legal advice before adopting the measure and had looked carefully at what other EU member states were doing in the same policy area.
He unveiled plans to limit EU migrants' access to welfare in Britain last month, saying he wanted eventually to restrict migrants from poorer EU states relocating to richer ones, stirring a row with the European Commission.
Iain Duncan Smith, Cameron's minister for work and pensions, said on Wednesday Britain planned to go "much further", saying there was broad agreement among most EU states that migrants shouldn't be able to claim welfare abroad until they began paying work-related taxes there.
Top-selling tabloid The Sun urged Cameron to "draw a red line on immigration" with the EU, warning that the country would otherwise vote to leave the bloc in a referendum promised by Cameron before the end of 2017.
The newspaper backed its call by publishing a YouGov poll which showed that 72 percent of Britons wanted Cameron to limit immigration from other EU countries.
Cameron is also under pressure from his own party on the issue, with some 80 of its 304 lawmakers urging him to extend restrictions on Romanians and Bulgarians working in Britain beyond the end of this year.
He has made it clear he can't and won't do that because it would be illegal under EU law.
In theory, citizens of the 28-nation EU have the right to live and work anywhere within it. But when Romania and Bulgaria, which are significantly poorer than the rest of the bloc, joined in 2007, nine EU countries imposed limits on this right for their citizens. Those limits expire on January 1.
In 2004, when Polish and other East European workers became eligible to work in Britain after joining the EU, the then Labour government predicted that only 13,000 people would come to Britain as a result.
Cameron said on Wednesday it had in fact "led to 1.5 million people coming to our country and was a profound mistake."
Labour, which is leading opinion polls, on Wednesday accused Cameron of "leaving everything to the last minute" and said he needed to urgently "beef up enforcement" of existing immigration laws.
A parliamentary committee on human rights warned Cameron separately that his overall plan to tighten immigration laws could lead to human rights breaches, homelessness and racism, charges he and his ministers have rejected.
European officials say they are confident they have averted a clash among EU leaders over migration at a summit this week, but the issue is likely to loom large over European elections next year.
Additional reporting by Justyna Pawlak in Brussels; Editing by Hugh Lawson and Sonya Hepinstall