British foreign secretary, Boris Johnson, is now aware of the scale of the false-claims' scam.

This week the Association of British Travel Agents, Abta, with the support of the UK and Spanish travel industry, launched a campaign to combat the boom in false holiday compensation, with a legal firm in Madrid threatening sentences of up to three years for people found guilty of trying to push through a false claim.

The Stop Sickness Scams has called on the new UK government to crack down on fake holiday sickness claims. Fake claims are costing the wider travel industry tens of millions of pounds and threatening to increase holiday prices and limit choice for honest British holidaymakers. Hoteliers in Spain and Turkey have already said they may have to stop offering all-inclusive packages to British tourists because of the devastating financial impact fake claims are having. Since 2013, there has been more than a 500% increase in the number of compensation claims for holiday sickness with tens of thousands of claims in the past year. Yet during the same period, reported sickness levels in resorts have remained stable and the problem is only associated with UK holidaymakers.

The foreign secretary Boris Johnson, has now come out in support of the campaign. In his Telegraph column, Johnson wrote: "Let me give you an example of an injustice that is unfairly affecting millions of families across this country. Back in March I got a letter from the head of the Association of British Travel Agents. It made my eyes almost start from their sockets. It seemed that in the past few years there had arisen a rampant culture of claiming insurance at the end of the holiday: not for theft, or for loss of valuables – but for an upset stomach. If the figures were to be believed, the digestive systems of the British people had become the most delicate in the world.

"We have all at some time been laid low by a dodgy prawn; but these numbers seemed outlandish. British travel agents were reporting a 434 per cent increase in claims for food poisoning since 2013, and one big tour operator said the numbers had gone up by 700 per cent. This was most odd, said the chief executive of the Association of British Travel Agents, since it was widely acknowledged that in the past 20 years there had been significant improvements in the quality and hygiene of the food in the resorts; there had been no corresponding increase in reported illness at the time; and of all the great tourist nations of the world it seemed that the British had suddenly become uniquely vulnerable.

"So Mark Tanzer of ABTA laid it on the line. These claims were very largely fraudulent, he said; and subsequent researches have shown that he is right. The phenomenon has been widely publicised, and some tabloid newspapers have dubbed Britain the "fake sick man of Europe". It seems that people have been simply sending off a form and claiming up to £5,000 a time in insurance, and all with no evidence more compelling than a receipt from a chemist to show that they have bought some local carminative or anti-stomach-bug medicine.

"This behaviour is infuriating for the hotels and tour operators, who feel that they have had to put up with unwarranted slurs on their kitchens. It is deeply unfair on those who genuinely do fall ill – since they may now find themselves the objects of unjustified suspicion. And of course, it is unfair on the vast majority of British holidaymakers whose costs - as Mr Tanzer pointed out - will inevitably rise to meet the burden of all these bogus claims. Some Spanish companies have even threatened not to accept British custom, so epidemic has been the scam."

Tanzer has welcomed Johnson’s comments.