Fewer than half of failed asylum seekers are removed from the UK and abuse of the system is rife, a new study claims.

Tens of thousands of people remained in the country despite their applications having been rejected or withdrawn, according to analysis by a former Home Office chief.

David Wood, an ex-director general of immigration enforcement, warned that Britain’s asylum system is “not efficient or very effective”.

The truth is that while there are thousands of genuine claims for asylum each year, thousands more are abusive applications

Former immigration enforcement chief David Wood

He said a myth is perpetuated in many countries that “the streets of the UK are paved with gold”.

The UK asylum system attracts in the region of 10,000 to 15,000 applications a year from individuals who ultimately have no valid claim, and under half of these are subsequently removed from the country, according to Mr Wood’s report.

It said: “The truth is that while there are thousands of genuine claims for asylum each year, thousands more are abusive applications.”

The assessment, which comes days after Home Secretary Sajid Javid sparked controversy by questioning whether migrants using small boats to cross the Channel are genuine asylum seekers, warned that abuse of the system risks undermining “well-placed sympathy” for refugees.

It said: “It is an important principle that people fleeing persecution should be given refuge by countries in a position to offer it.

“But where asylum processes are being used as a way of facilitating economic migration it is essential to be able to quickly and efficiently distinguish between the two, in order to ensure those entitled to help receive it quickly, and to ensure that UK citizens do not lose faith and support for a system that is rife with abuse.”

The paper, published by think-tank Civitas, said:

– A common “method of deception” is “nationality swapping”, whereby an asylum seeker will claim they are from a certain country to boost their chances of success;

– Another “area of abuse” is where applicants claim to be under 18 when they are older;

– A key difficulty in many removals is the absence of travel documents, which are often lost or destroyed prior to arrival in the UK;

– Many asylum claims are submitted when individuals are about to depart the UK, such as at the airport or on a plane.

Enforced removals and voluntary departures of failed asylum seekers have fallen from more than 15,000 annually in the mid-2000s, to fewer than 5,000 a year recently, according to the paper.

It said: “Of the 80,813 applications refused or withdrawn between 2010 and 2016, only 29,659 were removed – leaving 51,154 failed asylum seekers in the country from that seven-year period alone.”

Mr Wood made a string of recommendations to speed up the processing of applications and improve the rate of removal of those who are refused.

One measure would be to adopt new screening technology to allow interviewers to quickly identify “questionable areas” in applications.

Mr Wood called on the Government to step up efforts to challenge countries that refuse to provide travel documents for their nationals.

He also suggested the removals rate could be improved by detaining more of those who, at the end of an appeals process, are refused asylum and for whom it is known that papers could be secured.

The report said: “Some may and do argue that, irrespective of whether individuals in the UK are here legally or illegally, they should all be extended the hand of friendship.

“But if people do not want to see immigration controls enforced, then the honest thing to do is to campaign for an open-door immigration policy as such would be the effect.”

On the recent increase in attempts to cross the English Channel, Mr Wood warned that deploying more rescue ships could be “counter-productive” without an agreement that would see those picked up returned to France.

A Home Office spokesman said:“The UK has a proud history of providing protection to those who need it.

“However, we are clear that those with no right to be in the UK should return home.

“As part of the new asylum accommodation contracts we will be working with a charity to make sure failed asylum seekers are given information on the voluntary returns scheme, encouraging individuals refused asylum to return home.

“We will seek to enforce the return of those who do not leave voluntarily. Since the beginning of 2010 there have been over 345,000 enforced or voluntary returns.”

Dr Lisa Doyle, director of advocacy at the Refugee Council, said: “The fact that some asylum claims are refused does not mean that people are trying to abuse the system.”