Prime minister’s comments come as children’s commissioner Dame Rachel de Souza highlights ‘staggering’ inequalities in young people’s treatment across UK

Asked why the Lib Dems were opposed to a third runway at Heathrow when they professed to be in favour of growth, Cooper said she did not accept that a third runway would produce all the benefits its supporters claimed.

She explained:

On Heathrow, it is clear from looking at all of the economic analysis of airport growth over the last few years that many of the promises made by all sorts of different airport companies simply haven’t come to bear.

The promise of higher wage jobs hasn’t been substantiated. Often it’s lower paid jobs, and often not as many as they’ve claimed.