The desperate plight of Guantanamo Bay detainee Shaker Aamer received a massive boost yesterday when Barack Obama announced that he believed the prison should be closed immediately.

Mr Aamer, 47, has been imprisoned in the Cuban detention centre since February 2002 without trial or even being charged by the US authorities since he was captured in Afghanistan in November 2001.

But, during a White House press conference, US president gave the strongest indication of his stance on the matter by categorically stating that he believes the facility should be closed.

He also suggested the imprisonment of more than 100 detainees in "no man's land" was "contrary to who we are".

Mr Obama said: "It is not a surprise to me that we got problems in Guantanamo which is why, when I was campaigning in 2007 and 2008 and when I was elected in 2008, I said that we need to close Guantanamo and I continue to believe that we should close Guantanamo.

"I think it is critical for us to understand that Guantanamo is not necessary to keep America safe, it is expensive, it is inefficient, it hurts us in terms of our international standing, it lessen co-operation with our allies on counter terrorism efforts, it is a recruitment tool for extremists. It needs to be closed.

"Now, congress determined that they would not let us close it, despite the fact that there are a number of folks in Guantanamo who the courts said could be returned to their currently of origin or a third country.

"I'm going back at this and I've asked my team to review everything that is currently being done in Guantanamo, everything that we can do administratively and I'm going to re-engage with Congress to try to make the case that this is not something that is in the best interests of the American people, and it is not sustainable.

"The notion that we are going to continue to keep over 100 individuals in a "no man's land", in perpetuity, is contrary to who we are and it is contrary to our interests, it has to stop."

Mr Aamer and a number of other prisoners have been on hunger strike for more than 11 weeks now and the situation has become so desperate that detainees are being force-fed.

Tooting MP Sadiq Khan, who has campaigned tirelessly for Mr Aamer's release, said: "It is high time that this process of indefinite detention without charge or any prospect of imminent trial is ended for good.

"Guantanamo Bay is a disgrace and the sooner this institution is closed down the better.

"We all had high hopes in this regard from President Obama and it is disappointing that the President has still been unable to secure the closure when he said he would aim to do so in his first year in office.

"If President Obama does keep his promise to close Guantanamo, it is crucial that Shaker is brought back home to London, and not simply transferred to Saudi Arabia.

"To know that President Obama is listening to the concerns that I and many others have raised over the past eleven years is positive news, but what we urgently need now is action."

Mr Aamer's wife and five children, the youngest of whom he has never met, are British nationals and live in Battersea.