* Immigration is hot topic ahead of 2015 election
* Romanians, Bulgarians have right to work in UK next year
* Cameron is under pressure from UK Independence Party
* Policies would apply to all EU citizens moving to UK
By Andrew Osborn
LONDON, March 25 (Reuters) - Prime Minister David Cameron unveiled a crackdown on immigration on Monday, saying he planned to show illegal migrants "the door" and rein in welfare benefits he believes lure foreigners to live off the British state.
In a wide-reaching policy announcement, Cameron addressed public concerns about Romanians and Bulgarians winning the right to work in Britain next year, a prospect that has prompted the right-leaning press to warn of the arrival of "hordes" of welfare-hungry migrants.
"Net migration needs to come down radically from hundreds of thousands a year to just tens of thousands," he said.
Cameron's initiative reflects a change in rhetoric across the political mainstream, after years when talking about immigration was seen as taboo and the reserve of racists.
All three main parties now talk tough on immigration after polls showed it had become one of voters' main worries ahead of a 2015 election.
The success of the UK Independence Party or UKIP, which campaigns against "open-door" immigration and humiliated Cameron's Conservatives in a vote for a parliamentary seat, has added to the pressure for policy change.
Fines for employers who hire illegal immigrants will be doubled and landlords who let housing to illegal immigrants could also face fines, Cameron said.
"Put simply when it comes to illegal migrants, we're rolling up that red carpet ... and showing them the door," Cameron told an audience of students at University Campus Suffolk in Ipswich.
Cameron said he wanted to stop Britain's welfare system being "a soft touch".
In measures that will apply to all citizens of the European Economic Area (EEA) - the 27-nation European Union plus Norway, Iceland and Liechtenstein - immigrants will have to wait up to five years for social housing and will be subject to tougher "reciprocal charging" requirements when using the National Health Service - meaning their own country will have to pay.
Cameron said public fears about uncontrolled immigration - including the lifting of EU freedom of movement restrictions on Romanians and Bulgarians next year - and the resulting pressure on public services and the rapid pace of change were fair.
"These concerns are not just legitimate - they are right and it is a fundamental duty of every mainstream politician to address them."
"SOMETHING FOR NOTHING CULTURE"
Announcing new measures to make it more difficult for EEA nationals to claim welfare benefits, Cameron said payments would be stopped after six months if recipients could not show they had a genuine chance of getting a job.
He also said newcomers would face a much harder test to see if they were eligible for income-related benefits.
"Ending the something for nothing culture needs to apply to immigration as well as welfare. We're going to give migrants from the EEA a very clear message," he said.
In Brussels, a spokesman for the European Commission said the EU executive would need to ensure any proposals were legal.
Cameron said he would contest any challenge "very robustly".
Last Friday, Nick Clegg, the deputy prime minister and leader of the Lib Dems, said Britain was also considering obliging visitors from "high-risk" countries to pay a returnable cash bond to deter them from overstaying.
Nigel Farage, the leader of UKIP, said on Saturday that the unexpected success of his own party had shifted the debate on immigration, bringing it into the mainstream.
"If UKIP had not taken on this immigration debate, the others would not be talking about it at all," he said.