Dr Martens is to step up the price of its boots by 6%, as it says the cost of labour, energy and supplies, including the bouncy soles and leather, has risen. The Northamptonshire-based footwear group will increase prices for the second year in a row on the classic boot, which currently costs about £159, adding £10 to the price. The rise will come next autumn to reflect higher production costs that the company has now locked in over the course of next year. Staff costs are rising, and Dr Martens is offering a £500 cost of living bonus – paid out over October and November – to about 2,000 of its 3,500 workers around the world. Wilson said the company was making the payment as its workers were facing “very tough levels of inflation” around the world: “At the end of the day, people are the differentiator. We have a highly engaged workforce and wanted to show we cared for people who work for Dr Martens, and actions speak louder than words.” Shares dived almost 24% as the company warned of “variable trading” in recent weeks, partly because of mild autumn weather in the UK and Europe, and said that profit margins would take a hit.