Pity the Guantánamo Bay detainee: he is the easiest target for the politicians who wish to be seen “doing something” about terrorism, but who are entirely indifferent to these men’s lives or whether continuing our failed policies there will make anyone safer.

The latest example: four Senators, who on Tuesday introduced another bill seeking to cut off any funding which could allow detainees – including men long cleared for release by federal agents – to leave this legal black hole. One of the four is John McCain, who campaigned for president in 2008 saying that the detention center at Guantánamo needed to be closed.

Their ill-judged push comes just as the Obama administration seems finally to have the diplomatic wind at its back on Gitmo transfers. On Wednesday night, the Department of Defense (DOD) announced the transfer of five men cleared to leave for years to Oman and Estonia; that follows the December transfer of my client, Abu Wa’el Dhiab, and the five others to Uruguay. The Pope has signalled he is ready to help negotiate further releases; UK Prime Minister David Cameron, who is meeting President Obama at the White House on Thursday, has promised to push the case of Shaker Aamer, Reprieve’s client and the last Briton held in Gitmo.

All this positive progress is likely the chief motive for introducing the bill: if there are too many fresh success stories, enough Americans will see that former Guantánamo detainees are just regular human beings whom their government has demanded they nonetheless fear. But even the release of the latest five men leaves dozens of cleared prisoners still behind bars in Guantánamo.

Still, Senators McCain, Kelly Ayotte, Lindsay Graham and Richard Burr seek to stop the transfers people whom six federal agencies have unanimously declared not to be a threat to willing host countries – but Ayotte described the bill as barring the use of Congressional funds to transfer any “high-to-medium threat” terrorism suspects. That’s simply not true: it would block the release of anyone who has ever been thought to have been a threat by “Joint Task Force Guantánamo”, even if they’ve since been ruled innocent.

The legislation not only seeks to second-guess the unanimous judgement of six federal agencies – including the DOD, Central Intelligence Agency and Federal Bureau of Investigation – on who can be safely released; it also replaces that judgement with the perspective of Joint Task Force Guantánamo, the Elmer Fudd of the US intelligence apparatus.

Worse though, it isn’t even asking for the task force’s current view; if you have ever been suspected by the JTF of being “medium or high” risk, then even if you were later cleared under George Bush’s military reviews, you can never be released.

A number of plainly innocent men – including several transferred under George W. Bush’s presidency – would never have been released if this law had been in effect. Take Reprieve’s client Sami al-Hajj, the al-Jazeera cameraman picked up covering the war in Afghanistan, released without charge in 2008 after a year on hunger strike. The JTF decided at one point that he was a “high” threat – and, though he wasn’t, the authorities interrogated him hundreds of times about his work for the news channel.

Ayotte said, too, that “now is not the time to close Guantánamo”. She’s right: the time to close Guantánamo was years ago. McCain was right to campaign on the closure of the prison in 2008 – and he’s wrong now to claim the opposite. The Chair of the Joint Chiefs of Staff, General Martin Dempsey, was right when he called it “a psychological scar on our national values” and called for closure. General Mike Lehnert, who opened the camp in 2002, was right when he said he now wants it shut. All of the many other former military prosecutors, other servicemen and women and distinguished diplomats who said that maintaining the detention facility at Gitmo is damaging our name and our security and ought to be closed were all right.

This legislation is nothing but a transparent effort to score political points and keep the post-9/11 fear-industrial complex spinning. Its passage would damage America’s world standing and destroy the lives of dozens of cleared prisoners and their families – but in a Republican-controlled Congress, there is a real risk that it could pass.

Obama needs to signal that he will veto this bill, and the sooner the better. He should also remind the Senate –as he previously has in previous signing statements – that these laws are an unconstitutional infringement on his powers to release wartime detainees. And he should do what the sane majority of us on this planet have for years been hoping he will do: keep his early promise, release all the cleared men still held at Gitmo and, ultimately, close the prison.