David Cameron is in Israel, so both sides fielded their no 2 for Prime Minister's Questions. Some people groan and assume that Nick Clegg versus Harriet Harman cannot possibly be as interesting as the real thing. But the real thing was so dull last week that no one can remember it at all, and today's exchanges were much more revealing. One thing that they revealed was how passionately anti-Labour Clegg has become. Labour’s “sweetheart deals with the private sector” and “Mid-Staffs” were his defence to questions about the NHS.
At one point he was taunting the Labour side, asking them rhetorically to guess what the top rate of tax was during the years they were in government. "Anybody? Anybody? Forty p for 13 years!" he said. "Now she's complaining it's 5p higher!"
Later on, Kevin Brennan, the Labour MP, made fun of the Lib Dem council candidate coming fifth behind someone running for the "Bus Pass Elvis" party, telling Clegg, "You ain't nothing but a lap dog." The Deputy Prime Minister ranted back: "At least we're not the lap dogs of the bankers."
Quite hard to see how Clegg could ever lead his party in coalition with Labour after that.
What was more surprising, though, were the attacks on the absent principals on both sides. Peter Bone, the Conservative MP, asked a partisan question of "the stand-in prime minister" about which of the four main parties (he included Ukip) could deliver a referendum on Britain's EU membership. "Which of the party leaders trusts the British people and is a real democrat?" In reply, Clegg departed from what I thought the convention was - although I admit I have just made it up, because the rules of peacetime coalitions are not well established. The Deputy Prime Minister quoted what Cameron had said when he was resisting an in-out referendum. It may not have been unconstitutional, on second thoughts, but it was quite discourteous. While the Prime Minister was abroad, his deputy, standing in for him in the Commons and representing the Government, quoted him as a party leader against his party's current policy.
Even more shocking, though, was John Woodcock, the MP who last year stood down from Labour's front bench, who said that the whole House bore a responsibility for the Government's "shameful failure to intervene" in Syria. That sounded like an attack on his own absent leader, Ed Miliband, who had led his MPs to vote against the Government in August last year, which forced Cameron to withdraw British support for possible American strikes to punish the Assad regime for the use of chemical weapons - and which helped to persuade Barack Obama in turn to decide against them.
While the leaders are away, the silent and the loyal suddenly find their voice.