Ministers are wrestling with Britain's immigration headache later, as Ed Miliband again tries to make some headway with voters on the issue.
The opposition leader will again try to distance himself from New Labour's record on immigration in a party political broadcast, after ministers mull over the government's options to curb the impact of immigration on the benefits system in Whitehall.
Deputy prime minister Nick Clegg will chair a Cabinet sub-committee meeting, assessing ways in which the government could limit the impact of new arrivals from the European Union.
Conservative backbenchers, in particular, are becoming increasingly jittery about the potential influx of new arrivals from Romania and Bulgaria after a negotiated restriction on immigration from those countries expires at the end of the year.
One Whitehall source told politics.co.uk the government was a long way from establishing policy on the issue.
While officials do not want to single out Romanians and Bulgarians for discriminatory treatment, the government can distinguish between EU and non-EU immigrants for the simple reason that different rules for EU citizens already apply.
Immigration minister Mark Harper will report to the committee on whether there are any ways the current system of rules is being enforced properly, and on whether any further measures can be introduced.
Plans under discussion include extending ID card controls to make sure immigrants are eligible for benefits, making new arrivals wait longer before they can claim benefits and pushing ahead with a right-to-reside test.
The latter could be discriminatory against EU nationals, reflecting the British government's fear that some of the measures under active consideration could be challenged in the European court of human rights.
The coalition is thought to remain completely unified on moves to curb immigration and the benefits bill at the same time.
But it will face a political challenge on the issue this evening when Miliband uses his 'one nation' tag to package up a renewed pledge to be tougher on the issue.
Labour lost countless seats during the 2010 general election campaign because voters on the doorstep felt the party had not done enough to stop the arrival of immigrants from the EU in the mid-2000s.
Miliband made two flagship speeches on immigration last year in which he acknowledged the last Labour government's approach was ultimately unsuccessful in winning support from the British people.
He is expected to argue that low-skill migration in the UK is too high and needs to be brought down - and pledge to make English language teaching a priority.
"I'm going to tell people what I believe. And I believe that diversity is good for Britain," Miliband said ahead of tonight's broadcast.
"But it's got to be made to work for all and not just for some. And that means everybody taking responsibility, everybody playing their part and contributing to the country. That is what 'one nation' is all about, and that’s the Britain I want to build."