Hundreds of holidaymakers were stuck in the Channel Tunnel for six hours in sweltering heat when their train broke down.

Around 500 passengers were stranded in the dark with no air-conditioning and temperatures of 30ºC when a Eurotunnel train ground to a halt midway through the tunnel last night.

Paramedics were shipped down the service tunnel to check on the passengers and trains were stopped in both directions. Several passengers, including children, passed out, and a sealed metal carriage door had to be prised open to allow cool air in. Bottled water ran out and the toilets stopped working.

Services in both directions were stopped while a rescue train arrived to pull the broken-down one out.

Passengers, who had boarded with their cars at 7.50pm on Tuesday, got to Britain at 2.30am Wednesday.

Eurotunnel has offered refunds to all passengers and free travel vouchers. But those on the train described the response to the incident as “shambolic”.

The incident also affected Eurostar services. Around 3,000 passengers in both directions were delayed by up to five hours.