Class 175s will be running on a Cornish branch line from later this month.

The units, built by Alstom some 25 years ago and cascaded to GWR from Transport for Wales, were already planned to be used on services on the Devon and Cornwall main line, and also on the branches to Barnstaple and Okehampton.

But GWR has now announced that the units will be used for the first stage of Mid Cornwall Metro, which goes live on 17 May and will mean a doubling of frequencies to hourly between Newquay and Par.

A special train for invited guests formed of a Class 175 is running from Plymouth to Newquay and back today, and its passengers include representatives of Network Rail and Cornwall Council.

Other changes in the May timetable on GWR include new overnight connections between Reading and Gatwick Airport and the opening of Okehampton Interchange later in the year.

GWR managing director Mark Hopwood said: ‘Rail is one of the most powerful tools we have for driving economic growth connecting people to jobs, businesses to markets, and communities to opportunity.

‘This new timetable is a statement of intent: we are committed to making our railway work harder for the communities we serve, not just as a way of getting around, but as a genuine engine of local and regional prosperity.

‘From the first trains of the Mid-Cornwall Metro to our 200th station, this is a milestone moment for GWR, and we are proud to be delivering it.’