Jordanian terror suspect Abu Qatada could be freed as his bid for bail is heard.
Qatada, described by a judge as Osama bin Laden's right-hand man in Europe, will have his application for bail heard by a senior immigration judge in London. The radical cleric is being held in a high-security prison while he fights deportation to Jordan over terror charges.
The hearing will be held before Mr Justice Mitting at the Special Immigration Appeals Commission (Siac).
Qatada's 10-year battle against deportation is in the hands of the British courts after the 51-year-old lost his attempt to make a final appeal to Europe's human rights judges earlier this month.
His lawyers immediately applied for him to be released on bail as it looks likely that deportation proceedings will still take many months.
The political situation in Jordan has also worsened in recent months, casting fresh doubt on the UK's ability to deport him, they claim.
Repeated failed attempts by UK governments over the last 10 years to deport the radical cleric have cost nearly £1 million in legal fees, Government figures show.
No figures have been given for how much Qatada has received in legal aid and some estimates put the cost of keeping Qatada in the UK, either in a high-security jail or closely monitored under strict conditions in the community, along with the legal costs of the fight to deport him, at more than £3 million.
Qatada, who is said to have wide and high-level support among extremists, was convicted in his absence in Jordan of involvement with terror attacks in 1998 and faces a retrial in his home country. He also featured in hate sermons found on videos in the flat of one of the September 11 bombers.
Since 2001, when fears of the domestic terror threat rose in the aftermath of the attacks, he has challenged, and ultimately thwarted, every attempt by the Government to detain and deport him.