Transport unions have called for greater security on the Tube after the bomb attacks on London.
The unions want extra staff and better technology
They want extra staff and improved technology on trains.
The Rail, Maritime and Transport union, the train drivers union Aslef and the Transport Salaried Staffs Association made the joint request.
The BBC's labour affairs correspondent Stephen Cape said the unions want a new "security" role created to take pressure off drivers in emergencies.
No 999 access
The rail unions said it was unfair for all the responsibility to be shouldered by one person, and precious moments could be lost in the event of an incident.
Unions also believe technology could also improve security on the underground, which is reeling after the bombs on Thursday which killed at least 36 people on the underground network.
Currently, Tube drivers using the in-cab telephone system do not have direct access to the 999 emergency services.
"Cameras could also be installed in carriages as another aid," Mr Cape said.
Guards were taken out of Tube trains five years ago.
In March 2004 plain clothes anti-terrorist police patrolled the Tube network for the first time in the wake of the Madrid train bombings, which killed 191 people.