PART of the M1 will be shut tomorrow during the early hours for police to carry out tests on speed enforcement cameras.

It will be shut between junctions 6a and 10 by Hertfordshire Police. The closures are northbound and southbound between Junction 6 and 8 from 3am to 7.30am on Sunday, June 5.

Signed diversion routes will be in place for road users and the motorway will be re-opened earlier than planned if possible.