Can ex-Tesco boss Drastic Dave refresh the fortunes of drinks giant Diageo?

City heavyweight has cheered the markets by taking helm at Guinness owner, but there may be forces he cannot overcome

• Diageo names former Tesco boss to lead turnaround push

On landing a new job, nothing puts a spring in the step like knowing that news of your appointment has inflated the stock market value of your employer by more than 2bn.

Dave Lewis could be forgiven for keeping that confidence-boosting figure front of mind as he faces up to the challenge of reviving Diageo.