Jack Straw said the surveillance watchdog, Lord Nolan, will give the prime minister an official report revealing that 1,763 phone and mail intercepts were authorised in 1998.

Lord Nolan's report will detail the phone taps used

The figure, which came to light in a Commons written reply, shows a rise of almost 3% on 1997's previous record of 1,712 taps.

But the final total could be higher still, because the the figure does not include bugging operations approved by Scottish Secretary Donald Dewar.

Scottish taps were included in 1997's statistics.

In 1940 - when the UK was at war - there were 1,682 sanctioned surveillance operations, which, before 1997, was the greatest number of taps.

The year of the Cuban missile crisis, 1962, at the height of the Cold War, there were just 338 taps.

Lord Nolan, Interception of Communications Commissioner, will disclose a total of 1646 telecommunications and 117 mail intercepts in his 1998 report, said Mr Straw.

'Changes being considered'

But the Home Secretary defended the system under which taps were granted, saying: "Each application for interception of communications is subject to careful scrutiny at a number of stages before a warrant is issued."

He said officials at four levels of the Home Office looked at applications before they were passed to the Home Secretary and they were often passed back to the security services for further work.

Mr Straw said: "This may, and occasionally does, result in a decision that the application should be withdrawn or that a warrant should not be issued."

He added: "My department is currently considering whether further changes are needed to the framework of controls on the use of surveillance."