Planned airport-style screening of passengers on mainline rail and London Underground stations will be discussed today at an anti-terror conference.
The Transport Secretary Alistair Darling will explain the proposed new scanning techniques to public transport bosses and security experts from around the world.
Trials of the new equipment are due to begin in the New Year at the Heathrow Express platforms on Paddington station in west London.
Further trials are expected to follow at a selected number of railway and Tube stations in a bid to examine the practicalities of the system.
The four-week test period at Paddington was initiated following a review of rail security after the Madrid train bombings which killed 191 people in March last year.
The head of Madrid's Metro and an Israeli security expert will also address the conference in London.
They will share their experiences of terrorist attacks with their London counterparts in the wake of the July 7 bombings in the capital which killed 52 people and injured 700.
The Department of Transport has stated that a small number of randomly chosen passengers will be asked to take part in the tests at Paddington. This would involve going through a X-ray machine or being searched either by a body scanner or with sniffer dogs.
Bags may be passed through the X-ray machines and the techniques being used will include the first use on the UK railway of body scanners using millimetre wave technology. This enables security staff to check for objects concealed under clothing.
When announcing the plans earlier this month, Mr Darling told MPs: "We cannot operate a closed system like we do at airports. But it is important that we reduce the risk to those passengers whilst recognising that people need to get about on the Tube and railway.
"It is equally important that we take account of the benefits that new technology could provide us.
"It could offer security benefits and this should not be disregarded and without due consideration. We have to be ready to look at whether this would help."
Mr Darling acknowledged that it was impossible to replicate airport-style security on the railways.
"What we are doing is looking at selected action at different parts of the network which we want to test," he said on the BBC Radio 4 Today programme.
"It seems to me to make sense that, if we can use things like selective screening where that's appropriate, or new types of CCTV or other actions - some of which is obvious, some of which is not quite so obvious - then we ought to do that because our objective all the time is to reduce the risk of terrorist attacks."Reuse content