The 186mph blast-off at St Pancras

The 186mph passenger service pulled out of the £800million station at 11.06 to mark the successful launch of the most celebrated engineering project in years.

The restoration of the Victorian station has been universally acclaimed and even environmental campaigners were on board to praise the project. To underline the occasion, hundreds of people gathered outside St Pancras - not to travel but just to see the first trains set off. With the new top speed, the journey to Paris is now just two hours 15 minutes, Brussels one hour 51 minutes and Lille one hour 20 minutes.

The 750 seats on the train were snapped up within 60 minutes of tickets going on sale in July. Most paid £59 for the return but some forked out £309 to go first class.

The first service was a "green train" highlighting the company's commitment to environmentally-friendly travel. Passengers included representatives of Friends of the Earth, which has formed a partnership with Eurostar. The company has set a target of reducing its carbon dioxide emissions by 25 per cent per passenger journey by 2012 A million tickets have been sold for journeys over the next month and Eurostar predicts a sellout Christmas and New Year with the opening of the £5.8 billion 68-mile line, now known as High Speed 1, between St Pancras International and the Channel Tunnel.

But Eurostar chiefs were keeping a watchful eye on strike action by French transport workers which has crippled the high-speed TGV train service across the country.

French rail chiefs have given preference to Eurostar and a full service is expected but British drivers are ready to take over in case their French colleagues join the strike.

Tom Parker of Eurostar said: "This is an historic day for UK rail. It's the first new rail line in 100 years and the first high-speed line."