Immigration: David Cameron outlines benefit restrictions
The prime minister is setting out plans to curb welfare benefits for migrants from the EU.
David Cameron will say EU migrants should have to wait at least four years before receiving benefits such as tax credits or council houses.
He will insist the changes, which he will seek if he is elected in May, are an "absolute requirement" in future talks over whether to stay in the EU.
It follows news that net migration to the UK has risen above 2010 levels.
In a long-awaited speech in the West Midlands, Mr Cameron will say he is confident that he can change the basis of EU migration into the UK and therefore campaign for the UK to stay in the EU in a future referendum planned for 2017.
But he will warn that if the UK's demands fall on "deaf ears" he will "rule nothing out" - the strongest hint to date he could countenance the UK leaving the EU.
The main proposals in the speech - which are dependent on Mr Cameron remaining in power after May's general election - are:
Stopping EU migrants from claiming in-work benefits, such as tax credits, and getting access to social housing for four years
Stopping migrants claiming child benefit and tax credits for children living outside the UK
Removing migrants from the UK after six months if they have not found work
Restricting the right of migrants to bring family members into the UK
Speeding up deportation of convicted criminals
Longer re-entry bans for beggars and fraudsters removed from the UK
Stopping citizens from new countries joining the EU from working in the UK until "their economies have "converged more closely" with existing members.
Mr Cameron will say the UK public's concerns about levels of EU immigration over the past decade are "not outlandish or unreasonable" and the changes will create the "toughest welfare system" for migration in Europe.
"We deserve to be heard and we must be heard," he will say. "Here is an issue which matters to the British people and to our future of the European Union.
"The British people will not understand - frankly I will not understand - if a sensible way through cannot be found, which will help settle this country's place in the EU once and for all."
BBC political editor Nick Robinson said Mr Cameron's welfare curbs were "a tougher version of an approach already set out by Labour and the Liberal Democrats" but the proposed four-year limit on benefits would be difficult to negotiate in Brussels.
But he added that ideas of a cap on the numbers coming in had been abandoned amid the realisation he could not get support from other EU leaders for it.