Tesco has announced that its recently appointed UK and Ireland boss, Charles Wilson, is to step down after being diagnosed with cancer in recent months.

Wilson is the former ceo of wholesaler Booker, bought by Tesco earlier this year. He took on the Tesco job five months ago.

The new ceo of the UK and Republic of Ireland business is now Jason Tarry, who will report in to chief executive, Dave Lewis.

Tarry’s previous role, group chief product officer for Tesco, will be taken on by Andrew Yaxley.

In a statement Tesco said: “The good news is that Charles is responding very well to the treatment and all the signs are that the treatment has been successful.”

To help ease his workload he will now focus on leading the Booker business, and he will continue to report in to Lewis.

The reshuffle comes as Tesco faces losing its number one spot in the UK grocery retail scene. Sainsbury’s, which is currently ranked second, agreed to buy the third ranked player Asda (owned by Wal-Mart) in April this year.