Sainsbury's has poached an executive rival at Marks & Spencer to take up a key role bolstering the grocer's brand.

Helen Buck has been appointed as brand communications director and will join embattled Sainsbury's in January. At present, she is head of general merchandise marketing at M&S.

Buck will report to Sainsbury's marketing director Stephen Nelson. A spokeswoman said: 'Her role will be to ensure that Sainsbury's brand is communicated effectively.' Buck's role is a new position, but she will effectively replace brand marketing director Jeremy Schwartz, who will leave in January.

Sainsbury's chief executive Justin King revealed in May that he had shelved plans to change the grocer's brand image and its 'Making Life Taste Better' slogan. He said he wanted to concentrate on getting operational basics right.

However, Buck's arrival shows Sainsbury's is aware that its brand position needs to be improved.