THE House of Commons often looks more like an unusual boarding school than the venerable Mother of all Parliaments. This week, as MPs go back to work after the summer break, rowdy fifth-formers have seized control of the playground and are yelling insults at the teachers.
The two big targets for their rhetoric are the prime minister, David Cameron, and his deputy, the Liberal Democrat leader, Nick Clegg. Both of them are facing an unprecedented barrage of abuse from their own MPs, who are understandably worried that they are heading for disaster at the next election.
The most personal and vicious attack on Mr Cameron has come from an ambitious MP, Tim Yeo, who commented bluntly: ''The prime minister must ask himself whether he is a man or a mouse ... does he want to be another Harold Macmillan, presiding over a dignified slide towards insignificance?
"Or is there somewhere inside his heart -- an organ that still remains impenetrable to most Britons -- a trace of Thatcher, determined to reverse the direction of our ship?''
Another backbencher, Brian Binley, was even ruder, describing Mr Cameron as a mere ''chambermaid'', running around under the control of the Liberal Democrats, while Nadine Dorries dismissed him as as ''patronising and sexist''.
Against this background of catcalls from rebellious ''supporters'', Mr Cameron is trying to finalise a reshuffle of his government to beef up its appeal to voters and demonstrate that it has the ideas and the energy to salvage the economy from near bankruptcy.
Opinion polls show that by far the most popular move in a reshuffle would be to sack George Osborne as chancellor, but the word in Whitehall is that his job is safe. No matter how many heads may roll elsewhere around the cabinet table and among the minor ministerial postings, it will be hard for Mr Cameron to make a short-term impact with them.
His coalition government is badly handicapped now by the near breakdown in his relations with his deputy. Nick Clegg is fighting to save his own job amid constant sniping from supporters of the voter-friendly business minister, Vince Cable, whose support for Mr Clegg in the media has been extremely lukewarm.
The latest blow to the unity of the coalition came yesterday when a rift opened up in the cabinet over the building of a third runway at Heathrow. The official government line is that there will be no third runway because of environmental and noise pollution worries. But while that stance was being maintained on Sky news by the foreign secretary, William Hague, a completely different position was outlined on the BBC by Mr Osborne.
HE said that all options should be kept open while the government tried to achieve ''a political consensus''. Ironically, there are soon going to be new measures to speed up tricky planning decisions in England and Wales to try to get major building activity under way. But no amount of schmoozing and legal clout will solve the intractable stand-off between those who think Heathrow has to be expanded to underpin economic recovery and opponents who fear it is a symbol of an unsustainable source of self-destructive ''growth''.
The Liberal Democrats are opposed to it, as is transport minister Justine Greening, whose Putney constituency is under one of the flightpaths.
London Mayor Boris Johnson has been enthusing about building a new airport over the Thames Estuary but it is hard to see how it could be financed in current circumstances.