From January 2014, the current restrictions on migrants from the eastern European countries seeking work in the UK will be lifted. Fears have been raised that tens of thousands of Bulgarians and Romanians could come to Britain, putting a strain on public services.
So far, the Coalition has admitted having an estimate for how many Bulgarians and Romanians might come to Britain but Eric Pickles, the Communities Secretary, suggested it was not reliable.
This is because the estimate given in 2004 about the number of migrants who might come to the UK from Poland and other new EU member states was wildly inaccurate.
However, Downing Street has subsequently said there is no estimate and that the NIESR think-tank, commissioned to look at the issue, will examine "impacts", not numbers.
Yesterday the Deputy Prime Minister appeared to echo Mr Pickles and suggest there was a Government estimate, but it was just not very reliable.
He said: "We've seen estimates but they are estimates. I don't think it helps public confidence in the immigration system if we start... I don't think we as a Government should start bandying around estimates which are at the moment not very precise; by definition they're not very precise." He appeared to hint that there could be a rethink if the forecasts did "become precise enough for us to believe that they merit being put out there".
Later, however, a spokesman for the Liberal Democrat leader said: "He was referring to the fact that there are estimates around; for example, from Migration Watch, which he has seen but which he does not think are robust.
"There are also Government figures on the numbers currently in the UK and the percentage in the UK compared to other EU countries. However, the Government does not have forecast figures or estimates on the number of migrants that could arrive from Romania and Bulgaria," he said. Chris Bryant, the Shadow Immigration Minister, said: "David Cameron's Government is in a hopeless mess on estimates for the number of people coming from Bulgaria and Romania – contradicting each other on who knows what, while at the same time refusing to come clean and to publish the figures they've had.
"They should trust the public's common sense and publish the impact assessment immediately so that we can all decide for ourselves whether the plans in place are adequate."
He added: "People are sick of governments making promises and politicians spouting warm words about immigration but doing nothing."