The radical Islamic preacher Omar Bakri Mohammed has said he will return to Britain - unless the government says it does not want him back.
The Syrian-born cleric left London for Lebanon on Saturday, amid speculation he was to be investigated for treason.
But he told the BBC he would return after a few weeks in the Middle East.
Deputy Prime Minister John Prescott, standing in for Tony Blair, said his message to Bakri Mohammed was: "Enjoy your holiday - make it a long one."
The self-styled sheikh, who ran the radical al-Muhajiroun group from Tottenham in north London until it was disbanded last year, is famous for praising the 9/11 hijackers as the "magnificent 19".
Recently he said he would not report a potential bomber to the police, claiming Islam "forbids" him. He said he would stop any potential attack himself, with the help of his "Muslim brothers".
Mr Prescott said the majority of people did not appear to want Mr Mohammed to be allowed back into the country.
He said: "At the moment he has the right to come in and out. That is the circumstances at present and we have to change situations in this country by law."
Sir Iqbal Sacranie, of the Muslim Council of Britain, said Bakri Mohammed's departure would bring joy and happiness to the UK's Muslim community.
On Monday - two days after the preacher left the UK - the Crown Prosecution Service was asked to consider if there was enough evidence to charge him.
It is understood the CPS is now considering his case, as well as those of fellow radicals Abu Izzadeen and Abu Uzair.
TRIO FACING SCRUTINY
Omar Bakri Mohammed, cleric for al-Muhajiroun. Its successor group the Saviour Sect being banned. Said he would not tell police if knew of UK bomb attack plans; supported Muslims who attacked British troops.
Abu Izzadeen, British-born, spokesman for al-Ghurabaa [the Strangers]. Would not condemn 7 July London bombings. Told BBC they would make people "wake up and smell the coffee".
Abu Uzair, former al-Muhajiroun member, told BBC the 11 September attacks were "magnificent". Said Muslims did not "live in peace" with the UK any more.
But Bakri Mohammed denied he had fled the country and said he had never committed any crime in the UK or elsewhere.
He told the BBC: "I don't want the British Government to keep using [me] to make a new set of rules to put pressure on the Muslim community, so I decided to go on holiday for four or five weeks to stay with my mother."
He said if the British Government wanted to charge him with treason, he "would be the first one to return and challenge the allegation".
Bakri Mohammed is thought to have dual Syrian and Lebanese nationality, but has indefinite leave to remain in the UK after gaining political asylum in the 1980s.
Last week the Home Office began a two-week consultation on expanding the circumstances in which foreign nationals can be deported or excluded from the UK.
It set out a list of "unacceptable behaviours" including preaching to foment, justify or glorify terrorism or "fostering hatred".
Ministers already have the power to exclude any non-UK citizen from the country if presence is deemed "not conducive to the public good", the Home Office said.
The home secretary could, at any time, widen the working definition of "not conducive to the public good" to cover those whose behaviour had been deemed "unacceptable" - without the need for new legislation, a spokeswoman told BBC News.
Members of the public who wanted to contribute to the public consultation process could do so via the Home Office website, she added.
Labour MP Andrew Dismore said Bakri Mohammed had been a "malign influence" in Britain for 20 years and that the country would be "better off without him".
He said: "I believe he could have been prosecuted for inciting race hatred a long time ago... Why he wasn't is a matter for the Crown Prosecution Service."
Last week Mr Blair said the al-Muhajiroun group and its successor organisations would be banned.
Abu Uzair and Abu Izzadeen were also expected to be investigated
Mainstream Muslim organisations have denounced his views, saying that he does not represent the true voice of Islam.
But there is doubt over what legislation the government should use to combat such radical preachers.
Lib Dem peer Lord Carlile QC, independent reviewer of anti-terror laws, said he did not think it would be appropriate to bring treason charges.
Betraying one's country has long been regarded as one of the most serious of offences.
The death penalty for the offence was abolished only in 1998 and it now carries a penalty of life imprisonment.