by business editor Trevor Sturgess

Overseas travellers boosted Eurostar in the first six months of the year as total passenger numbers edged up to 4.7 million.

The number of international passengers rose by 21 per cent to more than half a million. Eurostar said this was partly driven by a big increase in US visitors who see a trip on Eurostar as a key element of a European tour.

The international high-speed rail operator between London, Ebbsfleet, Ashford, Paris and Brussels said that despite the financial squeeze on consumers, they were giving priority to leisure travel.

Leisure sales revenue grew by eight per cent, with leisure passenger numbers up four per cent. Overall sales revenues rose by four per cent to £421 million.

Eurostar boosted passenger numbers even though the comparison was with the first half of 2010 when an extra 100,000 passengers switched from aircraft grounded by the ash cloud crisis.

Excluding the impact of the ash cloud disruption on the 2010 figures, underlying first-half 2011 sales revenues grew by 12 per cent.

Nicholas Petrovic, chief executive, said: "The growth in the number of travellers heading for London earlier in the year has gathered momentum and in the first half international bookings have gone up by over 20 per cent.

"With Royal Wedding fever, London 2012 and the Queen's Diamond Jubilee on the horizon, London is highly attractive and remains a 'hot' destination for international visitors."

Eurostar expects 950,000 passengers to travel on Eurostar this month (July) alone and has laid on more than 20 extra services this summer.