Marks and Spencer and WH Smith have cut back on trials of M&S food to go at WHSmith branches to focus on making operations slicker.

WH Smith marketing development manager Catherine Lister said: "We are working with M&S towards being able to guarantee customers all-day availability on core promise lines and improving visual merchandising, focusing on getting operations slicker."

Some 24 travel branches of WHSmith at railway stations, including two at airport arrivals areas, now carry M&S branded food to go sandwiches and a mix of salads, sushi, bagels and wraps, down from 33 last year. And a roll-out of the joint venture to bus stations, hospitals and airports in geographical clusters nationwide, announced by WH Smith last year, has not gone ahead.

Lister said space at the WH Smith travel stores is at a premium, which means that many of them could not support a profitable Marks and Spencer concession.

She said: "Each of our travel stores has its own planogram as space is tight. In the immediate future we want to establish better range rotation with M&S at existing stores, changing 10% of the food to go range every month. We are not planning on adding any extra stores at the moment."