A survey of more than 7,000 package holidaymakers showed the biggest companies, Thomson, First Choice and Airtours, which together account for 60 per cent of the market, generally perform worse than smaller operators.
Of more than 40 companies surveyed, Airtours and its sister company Aspro came bottom: one in five holidaymakers said they would probably or definitely not recommend them to a friend. The same poor rating was given by Cosmos customers.
Several companies owned by the third of the big operators, Owners Aboad, now called First Choice, ranked near the bottom of the table. They include Sunmed, Falcon, Olympic and Enterprise. Even Thomson, the market leader, was rated only average.
The survey found a decline in customer satisfaction compared with two years ago, with only 50 per cent saying they would definitely recommend their tour operators, against 55 per cent previously, The magazine says the slippage should worry an industry "battling to retain customers". However, eight out of 10 are likely to give their operator some form of recommendation.
Accommodation is the biggest source of complaint, with one in 11 customers dissatisfied. One in six had changes made to a holiday after booking - a figure described by the magazine as "unacceptably high", And one in seven were unhappy with representatives.
Changes by operators suggested they were "taking a cynical attitude towards the requirements of their customers", the magazine said.
Four out of 10 were given no reason for the changes and a "scandalous" seven out of 10 made no offer of compensation or the chance to cancel and rebook.
The top-rated operators, many of them smaller and specialist companies, were P&O Cruises, VFB Holidays, Eurocamp, Portland, Swiss Travel Service, Brittany Ferries and Virgin Holidays.
Patricia Yates, editor of Holiday Which?, said that since a holiday was often the biggest single purchase in the year, the choice could be crucial.
"The overwhelmingly loud message from our survey is the real difference between the highest and lowest-rated tour operators, " she said.Reuse content