Rachel Reeves’s growth plan comes under scrutiny from her own side

Yet ask Labour MPs – and only 33 are still around now who were in parliament back in 2009 – and many are adamant that there is a very big difference.

Like Rachel Reeves, these MPs believe the parlous state of the economy requires this project to finally get going, and to get going quickly.

Many of those Labour MPs most in favour of what the chancellor has said in her speech on economic growth are part of the Labour Growth Group, a new alliance formed last year to push the government to deliver major infrastructure projects and housebuilding as fast as possible.

MP Chris Curtis, the group’s co-chair, told the BBC: “Anyone worrying about the opposition the Chancellor will face should know there’s more than 100 MPs in the Labour Growth Group who are ready to back her every step of the way in bringing this bold vision to life.”

He added: “This speech was bullish and that’s exactly what it needed to be – bullish on the potential of our economy and in taking on those who will stand in the way of realising that potential.”

It is clear this afternoon that one person determined to stand in the way of Heathrow expansion is Sadiq Khan, the Labour mayor of London. His instant restatement of his opposition to the scheme – because of its “severe impact” on noise, air pollution and climate change – may well embolden Labour critics in the House of Commons, including within the government.

One senior government source insisted this morning that Reeves’s decision to publicly invite Heathrow to submit an application should be seen as just that – an invitation that will kick off a long process with plenty more opportunities for internal opponents to make their case.

Some inside Labour argue that there is a generational divide within the party on many controversial growth issues, including this one.

One member of the 2024 Labour intake told me this afternoon that they expected opposition to Heathrow expansion among Labour MPs to be limited mostly to “nimby boomers”.

Of course, Heathrow was not the only meaty part of the chancellor’s speech. There is some private unease among Labour MPs who represent seats in the Midlands and the north of England that the projects are mostly, but not all, located in the south.

Even one Labour MP for a seat in the south of England urged the government to talk not only about the benefits of the developments to Oxford and Cambridge, but also to stress the benefits for the communities in between the two cities – noting acidly that Reeves, Sir Keir Starmer and all the previous five Conservative prime ministers went to Oxford University.

While the response of Labour MPs will play a big role in determining how Reeves’s speech is assessed in Westminster, the actual delivery of her plans will rely in large part on private finance and local government.

The entire speech was designed to boost business confidence in Britain’s prospects. The decisions firms make over the coming weeks, months and years will help to show whether that was a success.