Boris Johnson has used his conference speech to vow loyalty to David Cameron - but immediately criticised his policies on aviation and tax.
The Mayor of London delighted activists with a typically joke-laden address in which he likened a Cabinet colleague to a jay-cloth and boasted of dancing "Gangnam-style" with the Prime Minister.
Attempting to quash "super-masticated" speculation over his leadership ambitions, Mr Johnson insisted Mr Cameron would emulate his own re-election success.
He said: "If we can win in a recession and wipe out a 17-point Labour lead, then I know that David Cameron will win in 2015, when the economy has turned round - and we are already seeing signs of progress - when people are benefiting from jobs and growth and the firm leadership you have shown and the tough decisions you have taken, not least coming along to hear this speech today.
"I was pleased to see that you called me a blond-haired mop in the papers. If I am a mop, David Cameron, you are a broom - a broom that is clearing up the mess left by the Labour government, and a fantastic job you are doing.
"I congratulate you and your colleagues George Osborne the dustpan, Michael Gove the jay-cloth, William Hague the sponge. It is the historic function of Conservative governments over the last 100 years to be the household implements on the floor of the house, so effective at clearing up after the Labour binge has got out of control."
On several occasions, Mr Johnson had delegates in gales of laughter with his exuberant delivery. As he ticked off the various products that London exports to the world - from cakes for the Champs Elysees to aerials for Korean TVs - he dreamt up the surreal image of himself and Mr Cameron dancing to South Korean pop hit Gangnam Style. "Gangnam Style is very good," he said. "The Prime Minister and I danced Gangnam-Style the other day, you will be shocked to discover."
Mr Cameron sat in the audience at the Symphony Hall for the speech, surrounded by photographers and TV cameras waiting to see whether his smile faltered.
Meanwhile, Mr Cameron is to use his speech to tell delegates that Britain can pull through the current tough economic period with "hard work".
The PM is expected to say: "It's tough. These are difficult times. We're being tested. How will we come through it? It's not complicated. Hard work. Strong families. Taking responsibility. Serving others."