TBH, I think a £5bn black hole is the least of Burnham’s problems.
The best thing any government could do now is to accelerate growth in the economy. But that takes steps that are politically out of a Labour PM’s reach with the party as it is.
Other than the economy, I strongly suspect the devolving of power and money, and ‘No. 10 North’, will die a quick death and Burnham will swiftly lose any shine he has now.
The reality of Burnham is that Labour were desperate to remove the millstone of Starmer and in replacing him they’ve fallen for the snake oil salesman who’s rolled into town.