Work to install underground cables between Nailsea and Portishead as part of the Hinkley Point C Connection Project began this week.

National Grid is building a new 57km high voltage electricity connection between Bridgwater and Seabank near Avonmouth to link new sources of power in the area, including Hinkley Point C.

The cables will run between Nailsea and Portishead substation and make up part of the 37-mile power line which will provide homes and businesses with low carbon energy.

More: Update on power line through Portishead and Nailsea.

National Grid's contractors on the underground cable, J Murphy & Sons Ltd, will start work at various locations building temporary entrances and access roads, developing access routes, and installing secure fencing around the whole of the construction area.

The first stage of the work began on Monday around Engine Lane and Hanham Way/Watery Lane.

Temporary traffic lights are in force, with pedestrian access towards the lower end of Hanham Way and Watery Lane.

J Murphy & Sons Ltd will excavate trenches to construct ducts and joint bays for the cables and installation and connection of the cables.

Access to the area will be controlled throughout the construction period and work is expected to be completed by autumn 2021.

Once the cables are in place, National Grid will remove the existing pylons and prepare to build new T-Pylons to the west of Nailsea.

This work will be completed by Balfour Beatty.

Campaigners battled against the pylons for a number of years, with protesters raising concerns about reduced property prices and the effect on the countryside.

More: Council vows to keep up cable fight.

Government officials gave the project the green light in 2016 after a five-year battle.

National Grid is removing the 132,000 volt overhead electricity line and building a new 400,000 volt connection between Bridgwater and Seabank.

Over 8km of the new connection will be placed underground through the Mendip Hills Area of Outstanding Natural Beauty, leaving it free of pylons.

The cables between Nailsea and Portishead will also be put underground.