Eurostar’s ticket sales are up 12 per cent in the first half of the year, thanks mainly to foreign visitors, in particular Americans.

The high-speed rail operator carried 4.7 million passengers between January and June 2011, raking in revenues of £421million.

Last year’s Icelandic ash cloud saw Eurostar run an extra 70 trains, carrying 100,000 passengers as flights were cancelled, possibly helping boost numbers this year as travellers chose the train by choice.

The cash-strapped economy may also be boosting Eurostar’s popularity as families choose to go on short, European holidays instead of long-haul trips.

Eurostar boss Nicolas Petrovic said: “Despite the pressures on household budgets, consumers are choosing to prioritise leisure travel over other discretionary purchases.”

“In this difficult economic climate, we are finding that customers attach even greater value to their leisure time and are protecting short breaks and time away with family and friends.”

However the biggest increase has been in international travellers, in particular Americans, who now see taking Eurostar as “an integral part of a European tour”, the company said.

Some 21 per cent more foreign visitors used Eurostar in January to June this year than last.