British ministers look set to spark a civil rights row today by unveiling detailed plans for tackling a major terrorist attack.
The Civil Contingencies Bill, part of the Queen's Speech, will lay out the emergency powers available to the police in responding to terrorist incidents.
It is also designed to streamline local and national responses to a possible outrage, natural disasters and other emergencies.
But even ahead of today's publication of the formal Bill by Cabinet Office minister Mr Douglas Alexander, MPs and peers warned that the government's plans have "potentially dangerous flaws".
Ministers' attempts to define an emergency as "an event which presents a serious threat to human welfare, the environment, political, administrative, or economic stability, and the security of the UK or part of it" were "too subjective and loose", they said.
Today, director of human rights group Liberty, Ms Shami Chakrabarti, echoed that concern about the draft Bill.
While everyone accepted that in the event of a major terrorist attack or a natural disaster the police and armed forces would need to act quickly to protect the civilian population, that was no reason to grant the Government a "blank cheque", she said.
"What we are concerned about is that the definition of an emergency is so broad that it could cover any contingency whatsoever. That is a very very disturbing trend.
"It gives far too much power to government itself to define what it considers an emergency.
"The previous legislation was actually quite specific about what is a civil emergency and what is not."
Last month an all-party committee of MPs and peers set up to examine the draft Bill's implications warned that the powers it conferred could be used to undermine human rights.
The committee said there was a "significant risk" that regulations made in an emergency under the Bill could infringe human rights.
"We recommend the Bill explicitly prohibit regulations which would contravene any inalienable rights protected by the European Convention on Human Rights or the Geneva Conventions," the members said.
Part of the proposed Bill would allow ministers to ditch any Act of Parliament in an emergency, they noted. They recommended that a number of Acts which "form the bedrock of our constitution" should be exempt from this measure.
British Home Secretary Mr David Blunkett, however, has defended the proposals, arguing that they simply update the 1920 and 1948 Emergency Powers Acts, and insisting "there is nothing Draconian about this."
Mr Blunkett said the Government was organising to respond not only to terror attacks, but also to major floods, and emergencies such as the fuel blockades of September 2000.