British planes are to carry armed guards after new alert

Armed undercover sky marshals are to be deployed on British airliners to counter heightened fears of terrorist attacks, the Government announced yesterday.

Highly trained police marks-men with special low-velocity weapons will be on undisclosed British flights to combat hijackers and other terrorists. Other possible measures include changes to screening at airports, improving the protection of airliners on the ground and security systems to prevent hijacks.

A joint statement by David Blunkett, the Home Secretary, and Alistair Darling, the Secretary of State for Transport, said the "responsible and prudent" tightening of security was in response to the increased state of terrorist alert in the United States. The Foreign Office also warned yesterday that terrorists could be in the final stages of planning an atrocity in Saudi Arabia.

The airline industry is sceptical about the benefits of marshals. There are no details on how many will be introduced, nor on which flights, nor whether airlines would be asked to contribute towards their cost. Airline pilots said marshals would make aircraft less safe and some captains might refuse to fly unless they knew whether armed police were on board.

America has been on a heightened state of vigilance for possible terrorist attacks for a week since Washington increased its national alert to "code Orange". Officials have pointed to increased intelligence "chatter" pointing to a renewed assault by al-Qa'ida, possibly even more devastating than the 11 September attacks. Fighters have been patrolling the skies above major cities and Washington also announced it was monitoring 30 cities for release of biological, chemical or radiological agents.

Proposals for sky marshals were announced a year ago, but the Department of Transport declined to give details and major airlines refuse to comment on issues of security. Mr Blunkett said: "I can assure the travelling public that if we believed it was not safe for them to travel or fly, we would say so. What we are proposing are some sensible additional security measures. Our police and security services are already operating at the highest levels of vigilance and doing everything possible to ensure the safety of our citizens at home and aboard. Public safety remains our number one priority."

Airline pilots warned that airport security on the ground remained dangerously lax. They demanded that pilots be told if an armed guard boarded their flights, and warned that captains would refuse to fly if they were not satisfied about the security of their aircraft.

Jim McAuslan, general secretary of the British Airline Pilots' Association, said: "We take security seriously. We will not put passengers or aircraft at risk. But we cannot agree with the Government's decision to put armed guards on aircraft because we believe this will do more harm than good. We do not want guns on planes. Security on the ground is where we stop people with guns coming on board planes. There are not enough staff, they are low-paid and a lot are contract staff. We want highly paid, highly trained staff who can stop these people getting on aeroplanes."

Marshals are common on flights in the US, and the Israeli airline El-Al has carried armed marshals on its flights for more than 30 years.

Professor Paul Wilkinson, from the Centre for the Study of Terrorism and Political Violence at St Andrews University, said al-Qa'ida was still a threat to civil aviation. "These measures are sensible given the genuinely higher level of threat that we are all facing," he said. "We are facing a much more severe terrorist problem and that calls for more stringent measures than we have used."

But David Learmount, operations and safety editor of Flight International magazine, said: "Exactly what is going to be achieved by having someone on board which will mean there are two armed people? Gunfight at the OK Corral straight down the aisle of an aircraft? Useful? I think it's stupid. This is nothing new. They have been deployed for a long time. If the politicians think they are reassuring the public by doing this I think they're achieving exactly the opposite."

Patrick Mercer, the Conservative spokesman on homeland security, welcomed the announcement, but called for a public information campaign to highlight responses to terrorist threats. The Liberal Democrat home affairs spokesman, Mark Oaten, added: "Everything must be done to secure safety. But the Home Secretary must make it clear if this is a reaction to new evidence, or a delayed response to previous intelligence."