M275 motorway 40mph speed limit for no-deal Brexit

A queue of 13 lorries waiting at Portsmouth Port would result in traffic backing up on the motorway

A 40mph speed limit has been introduced on the motorway to Portsmouth as part of plans for a no-deal Brexit.

The limit on the southbound M275 is aimed at managing congestion if the UK leaves the EU on Friday.

Hampshire and Isle of Wight's Local Resilience Forum is concerned about delays caused by extra checks to cross-channel ferries at Portsmouth Port.

Portsmouth City Council said the group was preparing for a "reasonable worst-case scenario".

A council spokesman said: "This [scenario] is a no-deal Brexit occurring on 12 April and the concern is traffic congestion arising from delays caused by extra checks to cross-channel ferries at the port, diverted traffic from Dover and the effect on surrounding roads.

"Congestion at the port will mean queues forming and a queue of just 13 lorries would see traffic backing up onto the motorway network."

The Local Resilience Forum, which includes emergency services, councils, businesses and voluntary groups, is required by government to develop a plan to deal with potential problems.

Check points for lorries will be introduced on Portsmouth's M275 and the A31 near Winchester to allow customs checks to be carried out in advance rather than at the port.

Part of the A31 will also become a contra-flow to allow lorries to be checked.

The speed limit came into force on Wednesday, with signs and checkpoints due to be installed over the next two nights.

If a Brexit deal is reached or a further extension agreed with the EU, the changes will be reversed, a spokesman said.