Class 374 ( Eurostar ) horsepower

Good Morning ,

Out of curiosity I was researching each locomotive / multiple unit’s overall horsepower - amazingly the class 374 e320 has 21,000 overall horsepower ( 32 x 670 hp motors )
Does this make the e320 Britains most powerful train … ? ( Horsepower wise )

Yes, 16MW is most powerful.

On Network Rail (rather than high speed tracks), the power limit is much lower. From memory electric locos are restricted to 6.4 or 7.5MW (unlike some European railways that allow 9MW locos)