The success of Pret A Manger is due to the UK public appreciating “the freshness” of its offer.

Chief executive Clive Schlee was talking to British Baker after it revealed plans to create 500 new jobs.

He said the chain had an excellent relationship with its bakery suppliers – including Fosters Bakery in Yorkshire – which meant it was able to provide the best possible sandwiches to its suppliers.

Commenting on the day the company reported a 17% increase in profits to £61.1m, coupled with sales of £443m, Schlee said: “I think people are noticing that when you make a sandwich fresh on the day you sell it, then that sandwich is superior. People are appreciating the freshness of our offer.”

And, responding to criticism from London Mayor Boris Johnson said that an increasing number of workers at food outlets like Pret were not “native Londoners”, he said the company had 15% more British employees this year than last year.

Pret plans to open another 50 new shops worldwide this year, up from 36 new launches last year. In the UK, Schlee said the company would be opening sites in Leicester, Peterborough and Tunbridge Wells.

However, he said the government has not helped the retail environment by refusing to shift its position on business rates.

He said: “The rates are not coming down. In some places we are paying less in rent than we are in rates which is just insane.”

The group - which was bought by private equity fund Bridgepoint in 2008 - has 323 stores, mainly in the UK, but with others in Hong Kong, the USA and France.