Ukip have dipped slightly in the polls since mid-November: they have slid from usually polling above 15 per cent to usually polling slightly below it.
Here’s what the latest figures tell us in four graphs.
Net migration was nearly 300,000 in the year ending September 2014
During the leaders’ debates in 2010, David Cameron committed to curbing immigration to the “tens of thousands”. After an initial fall in immigration under the coalition, immigration has surged back up.
Such levels of immigration are a recent phenomenon
Here’s how those numbers compare to the past.
Immigration from Bulgaria and Romania has jumped since controls were relaxed in 2013
These numbers are bound to play well for Ukip in the pubs of places like Castle Point, which we visited recently and where Ukip are hoping to win one of half a dozen seats in May.