An inquiry conducted by the former Sainsbury's chief executive, Justin King, will say that tour operators and ABTA, the industry body, need to fundamentally rethink the level of disclosure they provide to customers.

Mr King was asked earlier this year by Peter Fankhauser, Thomas Cook's chief executive, to examine the company's approach to issues including health and safety and crisis management following a furor over its response to the deaths of two children in Corfu in 2006.

Bobby and Christi Shepherd died from carbon monoxide poisoning caused by a faulty boiler, with an inquest jury ruling in May that they were unlawfully killed.

The jury said that Thomas Cook had breached its duty of care towards them after the company had been accused of obstructing their family's efforts to uncover the facts surrounding their deaths.

Repeated complaints about Thomas Cook's attitude finally led its chief executive to publicly apologise, but only after it emerged that the company had received a larger compensation payout than the family.

The company is working with Sharon Wood, the mother of the Shepherd children, on a new carbon monoxide awareness initiative, which is expected to launch within weeks.

In his report, Mr King is understood to make approximately 50 recommendations, including a demand for companies to more clearly identify the potential risk of carbon monoxide poisoning in brochures and online.

Mr King is said to have concluded that the changing nature of the holiday industry, with many consumers booking flights and hotel rooms separately through internet-based brokers, has led to intense confusion about customers' rights and the nature of the product they are buying, as well as companies' health and safety obligations.

Package holidays, traditionally sold by members of ABTA, the trade body, have dwindled as a proportion of the overall holiday market, meaning that many consumers do not enjoy the level of protection they assume, Mr King will say.

The former Sainsbury's chief is also understood to argue in his report that Thomas Cook should devolve more authority to frontline staff in resorts to help holiday-makers who encounter serious problems, and that its customer service requires significant improvements.

Originally set for publication in September, the company is understood to have decided to delay the publication of Mr King's report until after a cororner's report into the children's deaths.

David Hinchliff, who investigated the tragedy, said there was a risk that further fatalities could occur unless action is taken.
Some of Mr King's recommendations overlap with those of Mr Hinchliff, who called for safety checks to be conducted by qualified health and safety specialists rather than "often inexperienced and overworked" tour representatives.

Thomas Cook was heavily criticised over its response to the tragedy involving the Shepherd children, with its former boss, Harriet Green, accused of ignoring the family's request for a meeting.

She received a share award worth £5.5m during the summer after being ousted from the company last year despite saving it from the brink of collapse.

Sources said that Thomas Cook would commit to implementing Mr King's recommendations in full in its response to his report.
Speaking in May, Mr Fankhauser said: "In May I met Sharon Wood and Neil Shepherd, who lost their children, Christi and Bobby, in a tragic accident on a Thomas Cook holiday almost 10 years ago.

"In that meeting, I promised them that we would review our health and safety standards, as well as how we take care of our customers ordinarily and during times of crisis, so that no other parents would ever have to experience what they have gone through."

Thomas Cook declined to comment on Sunday, while Mr King could not be reached.