Freeview viewers in West Cornwall and the Isles of Scilly may need to retune their TV equipment on May 1 to continue watching some programmes.

Some Freeview channels are moving to new airwaves to allow for the future development of new mobile broadband services.

Following a decision by the Government, transmitters are being updated region by region as part of a major engineering programme being carried out between now and 2020.

The required changes will begin at the Carn Brea transmitter group shortly after midnight and Freeview channels will be off-air overnight until 6am. After this, any viewers receiving their TV signal from the main Carn Brea transmitter who find they are missing channels can retune.

Services from smaller local transmitters may be subject to disruption until late afternoon. Satellite and cable TV are not affected.

Around 139,000 homes are served by the affected transmitters. Freeview will be running an information campaign to prepare people for the change, including advertising and on-screen messages.

Retuning should be straightforward and some TV equipment will retune automatically. Some older aerials may need to be replaced to continue receiving all channels. Viewers may be eligible for free in-home support, including aerial work if needed.

Further updates will take place at the local Penryn and St Austell transmitters on June 19, following the completion of engineering work in neighbouring areas. On-screen messages will remind people about these ahead of the changes.

Anyone who needs advice, or who finds they are still missing services after retuning, can visit the Freeview website at www.freeview.co.uk/tvchanges or contact the Freeview Advice Line free on 0808 100 0288.

Further information is available online at www.freeview.co.uk/tvchanges