Tom Watson, Labour’s deputy leader, is calling for an inquiry into the leak of David Cameron’s “crony list” of honours nominations amid speculation it could have come from Downing Street.  Watson has written to the prime minister, Theresa May, demanding a Cabinet Office inquiryand asking her to confirm she would end the practice of outgoing prime ministers awarding resignation honours.  Related: Why has David Cameron’s honours list caused such a fuss?  “The names on the honours list were leaked in advance of a public announcement,” Watson said. “I have written to the permanent secretary to ask when a leak inquiry is going to be initiated. I trust such an inquiry enjoys your full support but for clarity, I’d be grateful if you could confirm this in writing.”  Cameron was criticised after his list of aides, donors and MPs for 43 honours and 13 peerages was leaked last week to the Sunday Times.  May was dragged into the row after it emerged she had the power to block the list, and because two proposed awardees had given money to her leadership campaign. One asked for his name to be withdrawn and the other was blocked by the House of Lords appointments commission.  Following a public outcry over the list, Bob Kerslake, the former civil service chief who oversaw the honours, suggested the prime minister could be stripped of the right to give away resignation honours.  “Given that there is now a separate committee to consider honours for political service, there is a question for me as whether the PM should also make direct nominations,” he said. “My main concern is to protect the main honours system that gives such pleasure to those who benefit from it and recognises some truly remarkable achievements.”  Government sources have since indicated May will want to “do things differently” to Cameron and look at abolishing the tradition of resignation honours.  Watson has demanded clarity, asking for the “process and timetable for removing the powers of outgoing prime ministers to shower their cronies with titles”.  In the letter to May, he said: “I was delighted to read reports in the Sunday papers that you are going to scrap the outdated and easily abused tradition of resignation honours lists.  “Your commitment to ending the current arrangements is very welcome. The impact of the changes will be of comfort to the people who have legitimately received honours for service to the UK.  “I would be grateful if you could outline the timetable for removing the discretionary powers of prime ministers to award resignation honours to their acquaintances and friends. How will the power be removed? It seems to me it may require primary legislation.”  Related: I'd ban honours for five years if elected Labour leader, says Owen Smith  Labour will of course cooperate with any emergency legislation required, he added.  On Sunday, Owen Smith, the Labour leadership challenger, waded into the debate by proposing a five-year ban on party donors, MPs, advisers and staff receiving honours until the system has been fully reformed.  The former shadow cabinet minister challenged other parties to follow his lead, saying the honours system needed to “reward selfless acts, not political and personal patronage”.  He said that if applied across politics, the rule would have blocked the vast majority of Cameron’s recent awards for donors, MPs and Downing Street aides.  It would also cover Labour’s peerage for Shami Chakrabarti, which has been criticised because she recently conducted an inquiry into antisemitism for the party.  A spokesman for Smith said: “Shami Chakrabarti is a highly respected human rights lawyers who has been a tireless civil liberties campaigner for many years,” he said. “The timing of her appointment to the House of Lords, however, was unfortunate in light of her role as an independent adviser to the Labour party.”
Deputy party leader Tom Watson also seeks clarification from Theresa May that she plans to abolish tradition for outgoing PMs