In a historic initiative that will incense civil liberties groups, David Blunkett, the Home Secretary, will lay the order before the House of Commons in the next 48 hours, to be followed by anti-terrorist legislation which will be rushed through in the next four weeks.

The order, which says the events of 11 September are 'threatening the life of the nation', will allow Britain to opt out of Article 5 of the European Convention on Human Rights, which bans detention without trial.

It will pave the way for indefinite imprisonment of foreign nationals who the Government suspects are terrorists, and comes less than 24 hours after warnings from America that Britain is a top target for Osama bin Laden's al-Qaeda terrorist network.

The move reveals the seriousness the Government places on the threat to Britain. Such orders can be used only in times of war or when there has been an event that puts the security of the nation at risk. Whitehall sources said the order would not be reviewed 'for at least a year'.

Internment was last used during the Gulf war against Iraqis suspected of links to Saddam Hussein's army. It has also been used against terrorist suspects in Northern Ireland and Germans during the Second World War. It is the first time the Government has sought such a major opt-out of the Convention, which is the cornerstone of human rights laws in the country.

John Wadham, director of Liberty, said it would seek to challenge the order in the Court of Human Rights in Strasbourg. 'This is a fundamental violation of the rule of law, our rights and traditional British values,' he said. 'There is no evidence of direct plans to commit atrocities against Britain.'

Government officials insisted this was a 'formal procedure' and did not signal a change in the level of risk to the country, but said the police needed more powers to detain suspected terrorists.

'Britain is closed to terrorism, and we will take whatever action we can,' the Prime Minister's official spokesman said. 'People will object to it, but we are absolutely determined to get the balance right between human rights, which are important, and society's right to live free from terror.'

Downing Street believes that the public will back the moves, which it says are necessary to maintain national security. Intelligence reports suggest a number of terrorists linked to extremist Middle Eastern organisations have attempted to enter the country using the cloak of asylum laws.

The official spokesman said a handful of people would be targeted by the new laws and they would be offered the opportunity to travel to a third country if it could be arranged.

Even suspects who attempt to travel through British airports can be detained if the new terrorism laws are passed.

The Government plans to rush the legislation through both Houses of Parliament by Christmas and is hoping for cross-party support.

The public emergency order will be the first of a series of controversial measures closing what the Government says are loopholes in the law. As well as internment, the terrorism Bill will contain new laws to tackle religious hatred and harsh sentences for people behind 'non-bomb' hoaxes, such as anthrax scares.

It will also contain new measures against money- laundering and a crackdown on bureaux de change, which are often used to move terrorists' assets, and will order banks to scrutinise and report on any suspicious transactions.

New bills on fast-track extradition laws and asylum reform are not now expected until the new year.

*The Home Office is also planning to seize passports from British Muslims who are planning to travel abroad to fight for the Taliban or Osama bin Laden.

Home Office Minister Angela Eagle has confirmed she will give 'serious consideration' to powers at present used against football hooligans trying to travel abroad.

The law allows action against 'a person whose past or proposed activities are so demonstrably undesirable that the grant or continued enjoyment of passport facilities would be contrary to the public interest'.