The accolade – organised by CMP, publisher of Call Centre Focus magazine and sponsored by Siemens – recognises the company's dedication to providing an excellent customer experience.

CMP said that the Thomas Cook sales centre was invited to join the Top 50 initiative from more than 5,000 call centres in the UK, due to its demonstrable commitment to customer service.

The business, which has offices in Peterborough, Falkirk and Glasgow, as well as a team of homeworkers, stood out thanks to the extremely positive feedback it received from customers, industry organisations and experts.

Thomas Cook's director of sales centres, Nicola Dunsmore, said: "We are delighted with this nomination, as it comes hot on the heels of our highly commended status for Best Large Call Centre at the recent CCF awards, the only travel company to be recognised in any way.

"We are passionate about customer service, and it is our mission to become the leading sales centre business in the industry."

Together with the other Top 50 call centres, it is now taking part in an independent mystery shopping exercise, where sales consultants will be contacted by 20,000 members of the general public to find out how they are really performing.

The exercise, which is being carried out by leading researcher GfK NOP, will measure each centre's customer service, based on the criteria that was agreed by a series of independent focus groups conducted in 2007.

The results will be revealed at a gala dinner in London tonight, when the top 10 call centres in the UK, along with the top performers in a variety of vertical markets, will be rewarded for their commitment and dedication to customer service.