The last British resident detained at Guantanamo Bay may leave the detention centre in the new year as part of Barack Obama’s long-delayed plan to close the base. The US president is urging the release of almost half of Guantanamo detainees, and will likely say the remainder should be held in America.

Shaker Aamer, who is a Saudi citizen but has lived with family in Britain, was captured by the Northern Alliance of anti-Taliban fighters in 2001. He said that he was in the region to work for an Islamic charity, but the CIA accused him of being a senior operative in Al Qaeda, saying he was a “recruiter, financier and facilitator”. They also accused him of being at Tora Bora with Osama bin Laden.

The Sunday Times reports that he is now one of 64 detainees to be cleared for release, with US officials indicating will be soon be sent home. Aamer’s lawyer, Clive Stafford Smith, said he will return to Britain: “I cannot believe they will not include Shaker, as it would be totally irrational. It’s very hard for them to come up with an explanation as to why this hasn’t been done.”

Ten detainees have so far been released this month, with several more to follow soon. Among those released have been four Afghans, four Syrians, a Palestinian and a Tunisian who was accepted by Uruguay.

Despite the push to close the prison camp, senior military commanders believe many inmates are still dangerous. Since 2002, 17 percent of inmates freed have returned to violence while a further 12 percent are also suspected of doing so.

Stafford Smith says that closing the base, one of President Obama’s first pledges when he was elected, has now become a matter of pride. “If you’re the most powerful man in the world and you can’t solve that when you’re commander-in-chief and it’s the military running it then there’s something awry.”

He accused US authorities of delaying Aamer’s release because he had witnessed torture at the Bagram air base. He also accused MI6 of undermining British Prime Minister David Cameron’s attempts to have him returned: “I think Cameron does want him back but what I’m not convinced of [is] that there isn’t someone whispering in the background, ‘This isn’t as clear as you think it is. Trust us we’re MI6’.”

“With all the complexities in the world over Guantanamo, the simplest case is Shaker. It’s time to send him back to London to be with his wife and four kids.

“He’s not dangerous and they cleared him ages ago. It’s purely a matter of what he saw and what he witnessed.”