One senior MP said: "Boris needs an old hand who's been around the block a few times and is able to tell him when he is about to do something stupid."
The warnings came as Tories seethed at being ordered to vote to rip up the Commons disciplinary system to save Mr Paterson from a 30-day suspension, only for the PM to stage a U-turn.
Last week's turmoil — Mr Johnson's 43rd U-turn in under two years — has caused deepening alarm among his closest supporters.
One said: "No10 is full of yes men who simply nod at every suggestion rather than say, 'Hold on a minute — this is bonkers'."
Another ally said: "It really is getting serious when John Major, perhaps one of the worst Prime Ministers in living memory, is openly taking a pot shot at us."
Sir John, who was in No10 at the height of Tory sleaze in the 1990s, said BoJo's regime was "politically corrupt" over the way it treats Parliament.
Ex-children's minister Tim Loughton, 59, has been touted as an ideal enforcer.
Lord Hague, John Whittingdale, Sir Michael Fallon, Nicholas Soames and Damian Green are also possibles.
PAJohn Major blasted Johnson's 'shameful' handling of the Paterson scandal[/caption]