Removal of failed asylum seekers has collapsed to a record low - adding to concerns that Britain is failing to get a grip on its borders.

Latest figures show the number of unsuccessful refugees booted out of the country has plunged by two-thirds since 2010, when the Tories came to power.

The figures will be an embarrassment for Prime Minister Theresa May, who pledged during six years as Home Secretary to tackle the growing problem.

Removal of failed asylum seekers has collapsed to a record low - adding to concerns that Britain is failing to get a grip on its borders. Pictured: A Romanian national is arrested

Even though there was an official backlog of more than 26,000 failed asylum seekers – deemed 'subject to removal action' – at the end of December, just over a tenth of that number were actually deported in 2016.

Critics said the damning statistics showed too many illegal immigrants were deliberately 'playing the system' to avoid being kicked out of the UK despite not having permission to be here.

Experts have also warned that the number officially awaiting removal is just the tip of the iceberg. Analysis by the Migrationwatch think-tank has estimated there are up to 1.1million foreign people living in Britain illegally.

The Home Office figures will further erode public confidence in a failing asylum system that is supposed to take a strict stance against those caught living in the UK unlawfully.

Yvette Cooper, Labour chairman of the Commons' Home Affairs Select Committee, vowed to hold ministers to account over the shambles.

The figures will be an embarrassment for Prime Minister Theresa May

She said: 'This is a big drop in asylum enforcement at the same time as asylum delays have gone up. Cases aren't being decided on time and immigration enforcement has fallen significantly too.

'If rules are not implemented and properly enforced in a fair and timely way then it undermines confidence in the whole system. Yet it seems to be getting worse.

'The Government needs to explain why this is still happening and why it hasn't been sorted out.'

Conservative MP Tim Loughton, who also sits on the committee, said: 'These figures reinforce the problem that there are still too many people in the country illegally and who are playing the system in order to evade deportation.

'If we are serious about reducing net immigration numbers and making sure that we welcome those to the UK who have most to contribute we need to up our game in saying goodbye more speedily to those who have abused our hospitality in the first place.'

Data released by the Home Office, which dates back to 2004, showed that last year only 3,446 failed asylum seekers were removed from Britain. This compared with 18,220 in 2006 when Labour were in power and 10,394 when the Tory-led Coalition came to power in 2010, itself equating to a 66 per cent drop.

Yet in 2016 alone, a total of 21,059 claims for sanctuary were refused – meaning they were eligible for being kicked out immediately.

The Government says the number who are 'subject to removal action' is 26,879. But this does not count thousands who are embroiled in appeals against rejection – some often launched as they are being put on a plane home.

Two years ago, it was claimed that a staggering half a million failed asylum seekers were in Britain indefinitely because Government cuts meant cash-strapped immigration courts could not afford to hear their appeal cases.

Latest figures show the number of unsuccessful refugees booted out of the country has plunged by two-thirds since 2010. Pictured: Migrants arriving in Greece

The number of forced removals of failed asylum seekers dropped from 10,881 in 2006, to 6,174 in 2010 and then 2,062 last year. Over the same time period, the number of voluntary removals plunged from 7,399 to 4,220 and down to 1,834.

Illegal immigrants who have entered the country without permission can claim up to £1,500 in 'reintegration assistance' including a cash 'relocation grant' of £500 if they agree to go home.

Those with children can claim up to £2,000 per person. The National Audit Office looked at costs of forcibly removing failed asylum seekers in 2005 and found that the average cost was £11,000.

Liberal Democrat foreign affairs spokesman Tom Brake said: 'It is shocking that this government and the Home Office cannot even do the basics. They are an utter shambles. This is another thing to add to Theresa May's record of failure.

'The Government needs to look again at these ridiculous figures and rethink how it can have an efficient deportation system.'

Lord Green of Deddington, chairman of think-tank Migrationwatch, which campaigns for balanced migration, said only half of the 50 per cent of people who were refused asylum were ever removed from the UK.

Yvette Cooper vowed to hold ministers to account over the shambles

He said: 'Clearly there has not been enough focus on this problem and not enough resources dedicated to it. As long as anyone who claims asylum has a 75 per cent chance of staying in the UK, legally or otherwise, there will continue to be queues in Calais.

'Public confidence in the whole asylum system will be severely undermined.'

The Home Office has said that its focus has been on deporting foreign criminals, including murderers, rapists and violent thugs, after they finish their sentences in jails in England and Wales.

Since 2010, more than 35,000 overseas offenders have been booted out, including 5,810 in 2015-16, the highest number ever.

However, a major cause of delay in removals of failed asylum seekers is bureaucratic. Many refugees have fled their countries without a valid travel document or destroyed their passport before entering the UK, meaning it can be difficult to prove their nationality – meaning that some people are effectively unreturnable.

The longer families stay in the UK without being removed, the more chance they have of winning a legal challenge on human rights grounds.

Last year then Home Office minister Richard Harrington admitted Britain was powerless to boot out thousands of people who do not have permission to be here.

In a stark indictment of the UK's porous borders, Richard Harrington said many could not be deported because they had 'no place to go'.

Ministers also suffered a blow in 2015 when they were forced to suspend the entire fast track asylum system amid fears it would be struck down by judges. It involved locking up asylum seekers where officials believe an application could be quickly resolved.

A Home Office spokesman said: 'The UK has a proud history of granting asylum to those who need our protection. Where someone is found not to need our protection we expect them to leave the country voluntarily. Where they do not, we will seek to enforce their removal.

'Through the Immigration Act 2016, we have made it more difficult for people to remain in the UK illegally by incentivising voluntary returns, introducing tougher penalties for illegal working, and restricting illegal migrants' access to services.'