Sadiq Khan clashed with James Cleverly on Tuesday over the timing of a tougher ban on zombie knives.The Mayor of London urged the Home Office to press ahead swiftly with stricter restrictions on the large blades.He said: “It is simply unacceptable that zombie-style knives and machetes are still on the streets of London and the UK eight years after ministers first proposed banning the sale of the blades.”But The Standard understand new legislation on this type of knives was already planned to be announced this week.A Home Office source: “The Home Secretary requested a meeting over a fortnight ago in which he was hoping to discuss the Mayor’s record on knife crime. He looks forward to hearing how Sadiq plans to reverse the 40 per cent increase in knife crime he has overseen in office.”The mayor renewed his call for action just weeks after actor Idris Elba accused politicians of not giving the issue “the focus it deserves”.