With crucial results looming, investors fear 25 years of dividend growth may stall this week as drinks firm battles major headwinds

“Good things come to those who wait” may have been an effective slogan for selling Guinness but City investors are demanding more urgency to slake their thirst.

With a crucial half-year results presentation likely to take place on Tuesday, their patience with the boss of Diageo – the global drinks company that makes the “black stuff” – appears to be wearing thin.