One in 10 of Britain’s most skilled workers are being lured from the UK and replaced by low-skilled migrants, causing a significant brain-drain, a report by University College London has found.

They are attracted abroad by higher wages and better quality of life, while in their place the UK has attracted two million migrants with low numeracy skills.

The UCL study also found that newly-arrived migrants are six times more likely to have never worked than those born in the UK.

Dr John Jerrim of UCL’s Institute of Education said: “Immigrants account for one in four of the 9.6 million working age adults living in the United Kingdom with low level numeracy skills.

“Immigration has therefore had its biggest impact upon the bottom end of the numeracy skill distribution; it has led to a significant increase in the supply of low skilled workers.”

Meanwhile, around 4.7 million Britons now live abroad, with an average of 300,000 per year joining them. The report found that between 1964 and 2011 some 684,000 “highly numerate” workers left Britain, and although a similar number of “very numerate immigrants” arrived in that time, they were dwarfed by the 2.4 million new arrivals with low numeracy.

Dr Jerrim added: “Although immigration from South Asia has added many highly numerate people to our labour force, immigration from the same region and Africa has added six times more people with low numeracy skills to the UK than those with high numeracy skills.”

MigrationWatch chairman Lord Green of Deddington said: “There has long been a level of emigration by highly skilled British workers, many of whom return later.

“Highly skilled immigrants help to compensate for this but they are not the problem.

“The problem is the mass immigration of low skilled migrants and particularly now from within the EU.”

The Telegraph reports that the research comes as official immigration figures released today heap further embarrassment upon the Prime Minister. Despite pledging to cut immigration to the “tens of thousands” during his time in power, latest figures show that 624,000 immigrants arrived in the UK in the year up to September 2014, up from 530,000 the previous year.

Home Secretary Theresa May appears now to have abandoned the policy, saying the government had been “blown off course” by the huge amount of immigration from within the EU over which the UK has no control.