British resident Shaker Aamer, 46, (pictured with his children) has been held at Guantanamo for 13 years without charge – and has been cleared for release

Britain’s last Guantanamo Bay detainee, Shaker Aamer, was given fresh hope of release last night as the White House insisted it was in the ‘final stages’ of drafting a plan to close the notorious prison.

Barack Obama intends to present his plan to Congress in the coming days, a White House spokesman told reporters

It is believed the President has been stung by criticism that he will leave office with his pledge to close the detention centre unfulfilled.

British resident Mr Aamer, 46, has been held there for 13 years without charge – and has been cleared for release. Mr Obama promised to close it on his first day in office.

The White House said closing the prison remained a priority as it was hugely expensive and its existence has provided a recruiting tool for terrorists.

Republicans in Congress have consistently opposed closure, arguing the prison is particularly necessary now with the threat from Islamic State.

However, Mr Obama’s spokesman said the President would veto a defence spending bill now being negotiated in Congress if it includes provisions that would make it harder to close the prison.

The president has acknowledged that Guantanamo has fuelled anti-US feeling around the world and damaged relationships with ‘key allies’.

But British MPs said Mr Obama himself was largely to blame for failing to free Mr Aamer.

A cross-party group of MPs who visited Washington said that US suggestions that there were ‘security considerations’ to releasing Mr Aamer to the UK were ‘deeply insulting’ as it implied Britain doesn’t have the ‘legal structures, the security and intelligence skills’ to keep tabs on him.

The fate of Mr Aamer, a Saudi-born married father-of-four from south London, has certainly soured relations with Britain.

Barack Obama intends to present his plan to Congress in the coming days, a White House spokesman said

David Cameron has called repeatedly for his release.

In April, US government sources said he might be freed as early as June.

Cliff Sloan, the former State Department official dealing with prison transfers, said there was no sound reason for delay. But he still remains captive. It is unclear how Mr Obama will close Guantanamo as successive attempts have been thwarted.

One option the president is reportedly considering is to use his executive powers to override a congressional ban on bringing detainees to US prisons.

An alternative that officials have been pursuing is to send the detainees to other countries such as Uruguay, Bermuda and Palau in the western Pacific.

Last week it emerged that Susan Rice, Mr Obama’s national security adviser, convened a meeting on how to close the prison before the president leaves office in 18 months.

Under the current rules, Congress must be given 30 days notice of any prisoner transfer and must be assured it does not pose any security risk.

Mr Aamer was arrested in Afghanistan in 2001 where he says he was doing charity work, and ‘brutally tortured’ at the country’s Bagram prison, said the MPs.

Mr Aamer was arrested in Afghanistan in 2001 where he says he was doing charity work, and ‘brutally tortured’ at the country’s Bagram prison, MPs have said

He was transferred to Guantanamo Bay the following year.

However, even if the prison closes, there is no guarantee Mr Aamer will be able to return to the UK.

A spokesman for the human rights charity Reprieve said last night: ‘It has to be hoped that this is not another false dawn.

'Closing the legal black hole that is Guantanamo has always been more a question of political will than having the right plan.’