IT was meant to be the holiday of their dreams, with two weeks in the sun at a luxury Turkish resort.

But instead, David and Janice Copping’s trip turned into a nightmare.

Their three children all fell ill, while an intestinal parasite lodged itself inside Mr Copping leaving him needing hospital treatment.

The family is among 584 British tourists whose cases are being heard in court as part of a huge legal action against one of Britain’s biggest travel agents.

On Monday, High Court proceedings started against Thomson’s and First Choice parent company TUI UK Ltd, which is accused of compromising the welfare of hundreds of Brits who suffered holidays from hell at the Holiday Village Turkey resort in 2009.

Many were left needing hospital treatment after contracting life-threatening bugs including e.coli and salmonella.

The Coppings, from Ladygrove, Didcot, set off on their £4,000 summer holiday to Sarigerme, booked through First Choice, with 12-year-old triplets Daniel, Oliver and Hannah in August 2009.

Mr Copping said: “The holiday village was nice enough in itself, and we were fine for the first few days.

“Then myself, one of my sons and my daughter all got diarrhoea.

“It was very difficult for all of us, although as an adult, I was able to cope with it better.

“It affected Daniel the worst. He had also broken his wrist four weeks before we went out to Turkey, so his arm was in plaster. He could not do anything in a hurry and was scared to go in the pool. It ruined his holiday.

“He says now that it was the worst holiday that he is every likely to have – even if he lives to be 100. Nothing could ever be that bad again.”

When Mr Copping continued to suffer diarrhoea six weeks after returning from Turkey, John Radcliffe Hospital medics discovered the giardia parasite had lodged in his small intestine causing giardiasis – an illness found in the Developing World when water supplies are contaminated with raw sewage.

When the family posted their experiences on the Trip Advisor website, they found hundreds of other First Choice customers had also fallen ill at the resort, and the case was taken up by the BBC’s Watchdog programme.

No one from TUI was available for comment.

Solicitor Clive Garner said: “The range of confirmed bacteria that people were exposed to was shocking.

“At the very least, these can cause excruciatingly uncomfortable and painful symptoms – at worst, they can kill.”