The government has signed a mutual assistance treaty with Jordan to ensure that radical cleric Abu Qatada can be deported, Theresa May has told MPs.
The home secretary said the treaty had guarantees on fair trials within it.
The government is doing "everything it can" to deport Abu Qatada, she said.
The move comes after she failed to get the case referred to the Supreme Court to reverse a ruling that the radical cleric could face an unfair trial if sent to Jordan to face terror charges.
Mrs May is to apply directly to the Supreme Court for permission to challenge that ruling.
The treaty would come into play should the Supreme Court reject the government's request.
The withdrawal of the UK from the European Convention on Human Rights is another option being explored by the prime minister, said Mrs May, who added that it was "sensible" to have "all options on the table".
But cabinet minister and former home secretary Ken Clarke dismissed that idea, saying it is "not the policy of this government".
Giving a statement to the Commons, Mrs May said the treaty would have to be ratified by the UK and Jordan.
She said she believed it would satisfy concerns that Abu Qatada would not receive a fair trial there, and there was now "every chance" of deporting the cleric.
However, Mrs May added that even once the agreement was fully ratified, Abu Qatada would still be able to launch a legal appeal. This could mean it may still be months before he is deported.
Mrs May told the Commons: "I believe these guarantees will provide the courts with the assurance that Qatada will not face evidence that might have been obtained by torture, in a retrial in Jordan."
Shadow home secretary Yvette Cooper said she was willing to work with the government towards Abu Qatada's deportation, but accused Mrs May in the past of "overstating her legal strategy, which has not worked".
On the possibility of the UK temporarily withdrawing from the European Convention on Human Rights, Mrs May said it was her view that the UK needed to "fix that relationship".
BBC political correspondent Vicki Young said any suspension of the UK's membership of the ECHR is almost unprecedented and the Lib Dems are insisting they would block it.
She said: "We're told that the failure to deport Abu Qatada makes David Cameron's blood boil and he's ordered ministers to find a solution.
"The best case scenario for the government is that the Supreme Court agrees to hear the case and rules that Qatada can be deported, but few think that likely."
Mr Clarke, a former home secretary, told BBC Radio 4's World at One programme: "If I was asked my advice on that by any of my colleagues I would say I don't think that's got the faintest thing to do with the case with Abu Qatada.
"It is not the policy of this government to withdraw either for any short period or any lengthy period from the European Convention on Human Rights."
'Denial of justice'
The Special Immigration Appeals Commission (Siac), which adjudicates on national security-related deportations, ruled last year that Abu Qatada should not be removed from the UK because his retrial could be tainted by evidence obtained by torturing the cleric's former co-defendants.
Mrs May had argued she had obtained fresh assurances that would guarantee the fair treatment of the preacher on his return to Amman.
But the Court of Appeal upheld Siac's decision last month, saying the lower court had not misinterpreted nor misapplied the law.
Government lawyers had stressed that Jordan had banned torture and the use in trial of statements extracted under duress.
But the Court of Appeal judges said Siac had been entitled to think there was a risk the "impugned statements" would be used in evidence during a retrial and there was "a real risk of a flagrant denial of justice".
The Supreme Court can reconsider Court of Appeal decisions if the justices are convinced there is a "point of law of general public importance".
On 17 April 2012, the home secretary told the Commons that, following fresh assurances from Jordan that he would get a fair trial, "we can soon put Qatada on a plane and get him out of our country for good".
Bids for freedom before the European Court of Human Rights and the High Court followed before Abu Qatada's successful appeal to Siac in November.
Abu Qatada was re-arrested and returned to Belmarsh prison in March, following an alleged breach of bail conditions, concerning the use of communications equipment at his home.