One of Pembrokeshire’s busiest trunk roads will remain closed to all traffic throughout an entire weekend in June to enable major road improvement works to be completed.

The 26-mile diversion will affect the A40 leading both in and out of Pembrokeshire and will come into force between 8pm on Friday, June 16 and 5am, Monday, June 19.

The closure will affect the section of road between the Penblewin roundabout and Llanddewi Velfrey.

People heading to top tourist destinations including Newgale, St Davids and Little Haven will have to take the A477 at St Clears and head towrdes Kilgetty before turning north and rejoining the A40 at Canaston Bridge.

The contractors undertaking the Welsh government project have confirmed that all emergency services have been informed of the major diversion and are ‘prepared’.

A special lane emergency vehicle route has been put in place which is not expected to adversely affect the emergency response times within the county.

The closure will enable engineers to connect the new section of the A40 to the old section at the tie-in point as part of the A40 Llanddewi Velfrey to Redstone Cross Improvements Scheme in Pembrokeshire.

Work started on the project in the summer of 2021 and is due for completion by autumn 2023.

A spokesman for the scheme, being led by Griffiths contractors, said the work had been timed to reduce disruption.

He said: "Due to the significant level differences between the existing A40 and new A40 the principal contractor will require a weekend closure.

"To ensure that minimal disruption is caused to local communities, commuters, and the local economy the closure has been scheduled for the weekend of June 16-19, 2023, outside of the summer holiday season. Preparation work is already under way to minimise the closure duration.

"The closure has been discussed extensively within the traffic management liaison group, which includes the key statutory authorities that use the A40.

"As a result it was identified that emergency services need to maintain a route through and therefore Henllan Lane located immediately south of the A40 will also be closed other than for listed residents living on the lane and emergency service vehicles."

Drivers are advised to follow diversion signs. Traffic management personnel will be stationed at Whitland and Penblewin roundabouts to assist and guide road users.

All heavy goods vehicles will be required to take the alternative South Wales Trunk Road Agency route via the A4076 and A477.