Speed restrictions near London on the main Penzance to Paddington line mean some timetables are being changed and other services delayed.

The engineering work coincides with the ongoing weekend maintenance programme to the mainline in Cornwall.

A spokesman for First Great Western, Tim Bowcock, said some disruption is inevitable.

He said: "It's very short notice but it has to be done.

"Our part as train operators is, while Network Rail are undertaking this work, to try and run as many services as possible."