"A £1.4bn bailout has been announced for Crossrail, as Europe's biggest infrastructure project is pushed back beyond its launch date of autumn 2019. London’s £15bn route, to be known as the Elizabeth Line, had originally been due to open this month. The rescue plan - the third this year - will be used to plug a predicted £2bn hole in the project's finances." And who's going to pay for it all? Why, the 'taxpayers who work hard and do the right thing' of course. 'Government heads will roll?' That'll be the day! https://www.bbc.co.uk/news/uk-england-london-46507417
Whose heads do you want to roll ? The government ministers who were in office when Crossrail was first proposed ? They're long gone. The current incumbents ? Why should they be held accountable for mistakes made years or decades ago ?
They can still be hauled back to account for their past actions; after all, Blair was? They won't be though, because they know too much.