Foreign Secretary Boris Johnson has waded into the fake holiday sickness claims debate, calling the issue an “injustice affecting millions of families”.

Writing in defence of the Conservatives’ policies in the Queen’s Speech, Johnson cited a letter he received from Abta chief executive Mark Tanzer.

He said that the “outlandish” numbers – referring to a 434% rise in claims across the industry – proved the “rampant culture of claiming insurance at the end of the holiday for an upset stomach” and compared the issue to that seen with whiplash claims.

The Queen’s Speech introduced a cap on the fees that claims management companies can charge in personal injury claims, but did not set out what that cap might be. And there was no direct mention of holiday sickness in the governments accompanying notes, despite reference to whiplash and the knock-on effect of more expensive motor insurance.

Labour has criticised the Queen’s Speech, with leader Jeremy Corbyn claiming prime minister Theresa May’s minority government has “no mandate” to lead the country after dropping key election pledges.

In his Telegraph column, Mr 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.”