The Home Secretary's promise to keep radical cleric Abu Qatada in prison until he is deported has been thrown into doubt.
Theresa May has insisted the application by the cleric's lawyers to prevent him being sent to Jordan should be thrown out by the European Court of Human Rights (ECHR) because it missed a three-month appeal deadline.
However, Labour has released advice from the research department of the Council of Europe - which is responsible for the court - suggesting it may have just beaten the deadline.
But the confusion over the appeal could lead to Qatada - once described by a judge as Osama bin Laden's right-hand man in Europe - being back on British streets in just a fortnight.
Mr Justice Mitting, the British special immigration appeals commission judge, returned Qatada to jail this week after a rapidly convened court hearing found deportation was imminent and the chance of Qatada trying to abscond had increased.
But, in his written judgment, he said if it is "obvious" in two or three weeks that deportation is "not imminent" he will reconsider bail.
The revelation came as the Government faced further embarrassment over the case when a note - sent to the House of Commons Library - emerged that appeared to back the Qatada team's appeal timings.
It was signed by Nathalie Chene of Secretariat of the Committee of Ministers Council of Europe.
It stresses the final decision on whether the appeal is admissible now rests with a panel of five judges from the court's Grand Chamber.
"The Othman (Qatada) case was supposed to become final on 17/04/2012 and, according to the information provided by the European Court, the applicant requested a referral to the Grand Chamber on the 17/04," the note said.
"So I would say that it just in time but of course the Court (panel) may decide otherwise."
Earlier, in the Commons, Mrs May was adamant that the appeal deadline had passed 24 hours earlier at midnight on Monday, April 16.
"The Government is clear that Abu Qatada has no right to refer the case to the Grand Chamber of the European Court of Human Rights, since the three-month deadline to do so lapsed at midnight on Monday," she said.
"The Government has written to the European Court to make clear our case that the application should be rejected because it is out of time."
On Tuesday, Mrs May announced Qatada had been rearrested and deportation proceedings resumed in the absence of any appeal against the court's ruling - issued on January 17 - that he would not face torture if he was deported to stand trial on terrorism charges in his native Jordan.
However, that night, at 11pm local time Qatada's lawyers lodged their appeal with the ECHR.
In the Commons, Mrs May accused the lawyers of using "delaying tactics" to hold up the deportation process.
Shadow home secretary Yvette Cooper called for Mrs May to "get a grip" on the "farcical" situation.
"I think this has been farcical, this week - it's been completely chaotic," she said on BBC One's Question Time.
"We all want to see Abu Qatada deported to Jordan as soon as possible within the rule of law, and I think he should be kept in custody in the meantime."
