Gwent Police have warned of "serious disruption" to drivers using the M4 and M5 on Monday 4 due to a planned fuel protest.
Organisers have indicated an intention to block the Prince of Wales Bridge, with the protest starting on the M4 at Magor services, junction 23A eastbound, and junction 20 of the M4 westbound.
Chief Superintendent Tom Harding, who is leading the policing operation said: “Gwent Police, and Avon and Somerset Police, are working jointly with neighbouring police forces and partner agencies to ensure emergency and critical services continue and to reduce disruption to both road users and local communities, however we are preparing for serious disruption throughout the day.
“I would encourage drivers to reconsider their journey, consider working from home and avoid the area where possible.
“The right to protest under UK law must be balanced with the rights of the wider community who may be affected. We have additional officers and support in place on Monday to ensure the protest is carried out in accordance with the law.”