India, July 9 -- BT and Vodafone would need at least five years to phase Huawei out of their UK networks if they are to minimize service outages and other disruption for existing customers, senior technology executives told a parliamentary committee today.

The new warning comes as authorities consider more stringent measures against the Chinese vendor following US moves to choke off its supplies of components made with American equipment or design expertise.

Amid concern Huawei poses a threat to national security, the UK government in January proposed restricting it to 35% of any radio access or part-fiber broadband network and banning it from the "core," the control center of the entire system.

Officials are worried it will not be abl...