The Nightstar was a proposed overnight sleeper service from various parts of United Kingdom to destinations in mainland Europe, via the Channel Tunnel. To run alongside the Eurostar, north of London day-time Regional Eurostar services which were never operational, the Nightstar was the last part in a round-the-clock passenger train utilisation of the Channel Tunnel. The Nightstar service was to have been operated by European Night Services, a company mostly owned by European Passenger Services (the then-named operator of the Eurostar service).