Rail bosses have blamed fire safety and anti-vandalism rules after passengers complained new uncomfortable seats feel like "solid metal".

Govia Thameslink admits the seats on the new Class 700 trains are considerably firmer than older designs. The seats have limited padding, because cushioning is deemed as a fire hazard by the Department for Transport (DfT), according to the rail operator.

They also have to be made from graffiti-proof material, which the operator admitted has a "firm feel". The DfT admitted its guidelines have made for less comfortable seats.

Travellers have complained the seats are hard and narrow, with some joking that they will be bringing cushions to sit on in future.