These figures are wildly out of line with previous academic studies which have shown that immigrants contribute far more in taxes than they take in public services.
A study by professors at University College London's last year found that migrants had contributed a net total of £25 billion to the UK between 2001 and 2011.
A separate study by the OECD found that immigration to the UK had wiped billions off of the public deficit.
The independent Office for Budget Responsibility also estimate that immigrants contribute around 0.25% to UK GDP.
These claims are all "simply wrong" according to Migration Watch (MW), who have published a lengthy attack on the UCL's figures on their website.
According to Migration Watch's chairman Andrew Green: "Our report finally disposes of the immigration lobby’s oft repeated claims that immigration reduces our tax burden. The total cost is high and increased dramatically between 1995 and 2011, providing no compensation for the overcrowding of this island which we are experiencing, largely as a result of immigration."
So do their claims stand up? Not according to the academics who conducted the studies in the first place.
According to the Centre for Research and Analysis of Migration at UCL:
"MW’s main criticism is based on a fundamental misapprehension of what we are doing. MW’s main argument builds on a serious misinterpretation of the way we estimate income tax contributions and NIC payments of immigrants. MW claims that we assume that migrant employees earn the same as the UK-born population, and that self-employed migrants contribute more than those who are in salaried employment. But at no point do we make any of these assumptions, nor is there anything in our paper that suggests that in any way. It is therefore puzzling to us why their piece attacks our work so violently, based on a complete misapprehension of what we are doing."
They also claim the new Migration Watch report is "based on a substantial amount of guesswork, does not provide clear indication of how their figures are computed, and is at times sloppy or simply wrong."
So did Migration Watch put any of their claims to UCL before publishing their new report? Apparently not:
"MW chose to circulate their critique to the media earlier this week without sending it to us so we have not had the chance to point out errors to them as we would have been able if they believed in conducting debate similarly openly. Although the report cites some of the reports that are critical of our work, MW has chosen to ignore detailed replies already made, notwithstanding the fact that they are easily available on the CReAM webpage [http://www.cream-migration.org/comments.php], were brought to their attention at the time, and already respond to some of their criticisms."
You can read their full rebuttal here.
Pro-immigration groups today joined the attack on Migration Watch's report.
"This is incredibly serious for Migration Watch," director of the Migration Matters Trust, Atul Hatwal said.
"We have internationally respected academics from one of Britain’s best universities saying that Migration Watch have made a string of simple factual errors and cannot even get the basic maths right in their report."
Verdict: Migration Watch's claims are based on assumptions that the academic experts on the subject say are false. Yet for some reason, the new report was released without first putting those assumptions to those academics.
Migration Watch's claims are also wildly out of line with previous academic studies and come from an organisation devoted to campaigning against immigration. Their claims should therefore be looked at in this context.