Siemens Velaro high speed EMUs are derived from the ICE 3 first used by Deutsche Bahn (DB) in 2000.

[9] Alstom said that it would "pursue alternative legal options to uphold its position", and on 4 November 2010 it lodged a complaint with the European Commission over the tendering process, who then asked the British government for "clarification".

[11] In July 2011, the High Court rejected Alstom's claim that the tender process was flawed and the resulting contract "ineffective" under the Utilities Contracts Regulations,[12] and in April 2012 Alstom said it would call off pending court actions against Eurostar.

[22] Eurostar have used the trains to expand its core operation between London St Pancras International, Paris Gare du Nord and Brussels Midi/Zuid.

To meet the prospect of increased competition through the Channel Tunnel (primarily from DB), it intends to use them to expand its network to Amsterdam, Frankfurt and Cologne, and more destinations in France.

[23] The first Class 374 set entered service in November 2015, ahead of the full launch of the new type; the receipt of the safety authorisation from the Intergovernmental Commission was received earlier than expected, allowing Eurostar to begin utilizing the type on a small number of services for in-service testing.

[26] Following Eurostar's merger with Thalys, the trains have also been used for routes in Mainland Europe, as a replacement for the aging PBKAs.

[30] Each set is formed of 16 coaches: In June 2024, unit 374017 & 374018 (4017 & 4018) was decorated with a special Paris 2024 olympic golden livery.