Julia Hartley Brewer clashes with Insulate Britain spokewoman Tracey Mallaghan, after the group reportedly warned it would "unleash hell" if its demands are not met.
It comes as London’s transport network has been granted a High Court injunction against the group aimed at preventing them from obstructing traffic.
Transport for London (TfL) said the civil banning order applies to 14 locations around the capital including some of its busiest roads and it follows several previous injunctions against members of the group.
