The independent body that oversees government financial decisions has revised up the estimate of how many people are expected to come to the UK through immigration. The Office for Budget Responsibility (OBR) now says the total net migration into the country will be 60 percent higher than they had expected.

From now until 2020 the OBR had expected 105,000 more people to come to the UK than left every year. But they now say the figure is likely to be much higher, at 165,000 annually.

The new figures will pile yet more pressure on David Cameron, who promised to get net migration down to the “tens of thousands”. The government has struggled with the target because EU rules give around half a billion people the right to settle in the UK.

According to The Times the OBR said it had adopted the higher figure “in light of recent news” and that major shifts in the numbers coming had created a degree of uncertainty in the estimates.

It continued: “Net migration in the year to September 2014 rose to 298,000, up from 210,000 in the year to September 2013.

“Our previous forecasts have been underpinned by the assumption in the Office for National Statistics’ low migration population projections that net migration will move towards 105,000 a year by mid-2019. A reduction over time seems consistent with the international environment and with the government’s declared efforts to reduce it. But in light of recent evidence, it no longer seems central to assume it will decline so steeply.

“So we now assume that net migration flows will tend towards 165,000 in the long term, consistent with the ONS principal population projections.”

Immigration is likely to be a major issue at the General Election in May, as voters express their concerns about the lack of controls at the border. Under current rules the British government is unable to deport European nationals, even if they engage in crime.

David Cameron has proposed a cut in benefits for those coming from Europe, whilst UKIP want to end the free movement of labour within the EU.

Lord Green of Deddington, the chairman of Migration Watch UK, said: “It is hard to believe that the arrival of foreign workers on this considerable scale has had no impact on the employment of British-born workers, notably young workers, among whom 16 per cent are still unemployed.”

Economic problems in the Eurozone and the upheaval in North Africa may lead the figures to be put up once again.