David Cameron attacked Jeremy Corbyn as a “small-c conservative”. Was this wise? Most of us are small-c conservatives about the things we know and love.

The Prime Minister was, admittedly, attacking Corbyn for being conservative about sink estates. But those estates were built because people weren’t nearly conservative enough about the slums they replaced, which in most cases could have been repaired and renovated rather than demolished.

Corbyn pointed out that home ownership has fallen since Cameron entered Downing Street. Cameron began his reply: “This is a challenge.” The word “challenge” is used by our political class to describe problems they have no idea how to solve. For which politician can advocate a collapse in house prices?

Like football supporters displeased by the performance of their team, Labour MPs started to drift out of the chamber before the end of PMQs. The only way for Corbyn to raise their spirits would be to announce his resignation.

Sir Alan Duncan (Con, Rutland and Melton) warned that the collapse in oil prices is “potentially catastrophic”: a pleasantly unfashionable view. He wondered how we can avert the destruction of the North Sea oil industry.

No one pointed out that at least if North Sea oil were to collapse, houses in Aberdeen would become affordable. Cameron instead rejoiced that there had been “a complete and utter collapse of the SNP’s policy”. We fear  it will end up being bad for his character to face so little serious opposition.

Dr Tania Mathias (Con, Twickenham) observed in a steely tone that by 8th January, nitrous dioxide pollution in London had exceeded the annual limit. She wanted a pledge from Cameron that there will be no expansion of Heathrow Airport until the nitrous dioxide level has been brought under control.

Cameron made an emollient rather than a defiant reply. Can it be that there will be no third runway at Heathrow after all? We small-c conservatives would be pleased if that were the case. For the building of Heathrow is another mid-20th-century planning blunder, almost as bad in its way as the sink estates.