The head of finance at Dyson Group, the FTSE 250 developer of high-performance materials has stepped up to become interim chief executive after the resignation of Patrick Lammers.

Julian Cooper has run finance for Dyson as an outside adviser since August and will step into the CEO’s job but on the basis of not joining the board.

Cooper is a former partner at Arthur Andersen. The group said his immediate focus will be on financial restructuring. A statement said he was “ideally suited” to the company’s shot-term needs

Christopher Honeyborne steps up from non executive director to executive chairman at the same time.