Brandon Lewis, the minister leading a cost-cutting drive at the UK’s £180 billion local government workers’ pension fund, said he was in “listening mode” over his reforms – but council officials reacted badly after he appeared to blame them for poor investment performance.

Earlier this month, Lewis unveiled proposals that could take as much as £80 billion of town halls' pension pots out of the hands of active stockpickers, and invest it in cheaper passive funds that simply track the market instead.