27/03/2014 11:33 GMT | Updated 27/03/2014 11:59 GMT

Theresa May To Cut UK Net Migration By 'Massaging' Immigration Stats, Critics Warn

British Prime Minister David Cameron and Home Secretary Theresa May, right, visit the UK Border Agency staff at Terminal 5 of Heathrow Airport, London where they were shown differences between fake and real passports Tuesday Nov. 23, 2010. Britain's Home Office says it will be announcing the country's permanent immigration quota _ a new limit intended to dramatically reduce the number of non-EU nationals permitted to work in the U.K. (AP Photo/ Steve Parsons, Pool)

Theresa May has been accused of trying to "make the figures fit the politics" over proposals to cut net migration by nearly 20,000 a year by shortening visas for foreign employees so they can escape being classified as migrants.

This attempted redefinition comes after work and pensions secretary Iain Duncan Smith backed down from trying to change how child poverty is measured and ministers were accused of "trying to change the goalposts" in an attempted reclassification of fuel poverty.

The Home Secretary is considering the move, which would exclude some immigrants by shortening the 12 month intra-company transfer visa, by which an overseas employee can be sent to a UK-based branch, to as long as 11 months and 29 days, according to the Financial Times.

This means that foreign employees would not qualify under the UN definition of net migration, as it only counts those staying for a year or more.

Jonathan Portes, director of the National Institute of Economic and Social Research, said: “The government has belatedly recognised the economic damage done by arbitrary limits on skilled migrants from outside the EU. So it's bending the rules and making a mockery of the policy - which is obviously absurd, but preferable to the alternative of trying to hit its own misguided target. Of course the sensible thing to do would be to drop the target entirely.”

The coalition's net migration cap has been an item of increasing potential political embarrassment as evidence mounts that ministers will fail to meet the Tories' pledge to cut the level of net migration - charting the amount of people coming to Britain minus those leaving - to "tens of thousands" by next May.

George Osborne's own Budget was revealed to be banking on the net migration failing, as the Treasury estimated that net migration would stay at 150,000 next year and remain well above-target for the following years.

A spokesman for the Institute of Directors told HuffPostUK: "This arbitrary cap is damaging to the growth prospects of UK PLC, and risks cutting British firms off from much-needed skills. The policy also risks putting off would-be entrepreneurs from setting up in the UK, as a dynamic and mobile workforce is in increasingly in demand.

“Rather than working out how to make the figures fit the politics, the government should focus on ensuring that our economy is truly able to compete in the global race.”

Atul Hatwal, director of the pro-migration pressure group Migration Matters, said: "This looks an awful lot like an attempt to massage the net migration numbers to meet a political target.

"At a time when the recovery is the priority and there are almost 600,000 unfilled vacancies across the economy, the government needs to think carefully about making it more difficult for businesses to hire the specialists they need, just to hit a political target."