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LONDON, England (CNN) -- British Prime Minister Tony Blair is being urged by opponents to spell out in detail the al Qaeda threat facing Britain.
Opposition Conservative home affairs spokesman David Davis called for a "detailed account" of threats and targets. He said it was "astonishing" Britons were getting more information from the U.S. than from their own government.
Davis also called for the appointment of a UK chief of homeland security to match Tom Ridge in the United States.
The Conservative spokesman issued the appeal after the Home Office described the threat as "real and serious" and the American authorities pinpointed specific targets in Washington, New York, and New Jersey -- all "iconic" financial institutions.
The UK Home Office indicated that no specific threat had been uncovered. Officials would only say Britain was in a state of "heightened readiness" after plans for terror strikes in the the U.S. and the UK were uncovered following the arrest of a senior al Qaeda suspect.
E-mails about attacks on both countries were on a computer belonging to Ahmed Khalfan Ghailani, wanted for the 1998 twin U.S. embassy bombings in Africa. (Information 'treasure trove')
The UK Home Office indicated that the emails did not constitute a specific threat.
"We are maintaining a state of heightened readiness in the UK," a spokeswoman said.
"We are taking every feasible precaution to protect British citizens here and abroad and, as ever, we keep the threat level under constant review."
Davis said in a statement that the Blair administration should be more forthcoming with information.
"The British Government should take this risk extremely seriously," he said.
"We find it very worrying that the Americans seem to be at a much more advanced stage than us in contingency planning and police presence. They also share much more information with their public than our government."
Davis said: "Mr Blair need to spell out the exact threat to the UK so that we are in a clear position as to where we stand. It is astonishing that we are getting more information about the risk to Britain from the Americans than from our own government.
"The raw truth is that local authorities are under-resourced and Britain does not have one person solely responsible for the job of keeping us safe against terrorists. The sooner we have a Minister for Homeland Security, the better."
Conservative shadow attorney general Dominic Grieve said that his understanding from the U.S. reports was that specific targets in the UK had been identified.
"The U.S. has shown a much greater readiness to inform people what is going on," he told Sky news.
He said Britons had been told for months it was not a question of "if" but "when" there would be a terrorist outrage in the UK.
"I think the public are entitled to as much information as possible which is compatible with intelligence requirements," he said.
He added that members of the public could be invaluable to police in being their "eyes and ears" to help prevent terrorist attacks.
Liberal Democrat spokesman Simon Hughes said that Britain traditionally had a more reserved approach to issuing terrorist alerts than the U.S., but if there were specific information a decision had to be made on whether it should be shared.
Kevin Rosser of Control Risks Group consultancy in London told Reuters Britain's approach "is not to make color-coded warnings, not to publish every possible threat, but work closely with institutions that may be affected to help them tighten security and address threats in the least disruptive way possible.
"The problem (with the American approach) is that it creates public anxiety. If the goal of terrorists is to spread fear and unease then to some extent they've done that job for them without anybody carrying out an attack."
Employees of some of the most famous financial institutions in the U.S. were urged to report for work Tuesday despite the "credible" threat from al Qaeda.
Intelligence gathered over the weekend pointed to a car or truck bomb, the U.S. authorities said. Potential targets were named as the Citigroup building and New York Stock Exchange, the International Monetary Fund and World Bank buildings in Washington and the Prudential building in Newark.
Security was increased after the U.S. government said that the new intelligence indicated meticulous planning.
In Britain no apparent extra precautions were being implemented in the City of London, the capital's financial district Tuesday.
Last week the Blair government launched a leaflet which will be delivered to all 25 million UK homes warning what to do in case of an emergency -- particularly a terrorist attack. (Full story)
The 22-page pamphlet is part of a massive £8.3 million ($15.3m) public information drive backed by a big TV advertising campaign..