Last week, John McDonnell said that Labour had fully costed its manifesto.  As Mark Wallace pointed out on this site, these weren’t the full costs, the only costs…or the last costs.

And so it has proved.  The Institute of Fiscal Studies points out that Labour’s scheme to pay older women adversely affected by the equalising of the state pension age would lead to “another £12 billion of borrowing every year for the next five years”, on top of what Labour has already promised to spend”.

The Institute’s Paul Johnson concludes that the move “drives a coach and horses immediately through the manifesto pledge to get to current budget surplus to remain at current budget balance.”  That’s one way of putting it.  Another is so much horses and a coach as a brand new T-14 Armata tank.

In short, Labour first said that it had fully cost its manifesto, and now casually chucks another £58 billion into the mix.  If the party really is so desperate as to tear up on Sunday what it promised on Thursday, so be it.  And where it has started, it could carry on (which it will anyway).

McDonnell might as well pledge £1 million to all comers.  He could make it £1 billion while he’s at it. It would be no more or less credible than all his other plans.