Question to the Department for Transport:

To ask His Majesty's Government whether they intend to upgrade the air conditioning on the diesel Class 158 trains between Waterloo and Exeter; and if so, when.

The Class 158 and 159 fleet heavy maintenance overhaul and internal refurbishment programme started in December 2025. The refreshed units will start being rolled out progressively later this year.

The Class 158 and 159 fleet refurbishment programme includes air conditioning and heating fan overhauls, door overhauls, toilet overhauls, refreshed interior paintwork and updated seat finishes throughout.