The Government is facing calls for the publication of an official report believed to suggest the impact of immigration is less than feared.
The study reportedly withheld by Downing Street advises “displacement”, or the number of British workers who are unemployed because of immigration, is much lower than the figure used by ministers of 23 for every 100 additional immigrants, the BBC's Newsnight programme has claimed.
The BBC quotes officials as saying the report was apparently completed last year but has not been published amid concerns it could prove politically controversial.
Research from the Migration Advisory Committee has been used by the Home Secretary Theresa May previously as evidence for claiming that “for every additional 100 immigrants […] 23 British workers would not be employed”.
But a study by civil servants has allegedly concluded that the “displacement” figure is actually much lower.
According to Newsnight, the new report has been looked at by external academics and agreed across all the departments involved in migration, which includes the Home Office.
Liberal Democrat MP Julian Huppert told the programme the report should be published “as quickly as possible”.
”We have to have the right figures, so we can make the right decisions, so that we get the best people here to help our economy,” he said.
Prime Minister David Cameron's official spokesman said the report would be published "shortly", and indicated that it was likely to appear before the European Parliament elections on May 22.
"Things are published when they are ready to be published, and the work has not been completed yet," the spokesman told a regular Westminster media briefing. "When it has been, I expect it to be published shortly."
Asked whether the PM thought it right now to drop his ambition to reduce annual net migration below 100,000, the spokesman said: "No. It is the objective which we are very much working towards."
Deputy Prime Minister Nick Clegg said he had not previously been aware of the report but that it would be published when it was ready.
"It is not a report that has percolated its way up to my desk. When it is ready, of course it will be published," he said.
"It is really important that the debate on immigration is based on facts. Where these statistics are complete, where they are credible, where they have been stress-tested, they should be put out into the public domain."
Shadow immigration minister David Hanson said: “The British people should have information made available to them so they can make a judgement about the impact of immigration on jobs.
“This should be done on the basis of fact, not more empty rhetoric or spin from the Government.”
This morning, the UK Independence Party leader Nigel Farage told BBC Radio 4's Today there was "no doubt" that British people "have lost their jobs because there is too much labour coming into the market".
He added:"The other factor, which is not in this report but is perhaps even more pertinent, is the effect on wages of people in work.
“We have had wage compression and it has meant lower wages for millions and millions of people.”
A government spokesman said: “We don't comment on internal government documents.”
Additional reporting by Press Association