The last few weeks in politics have revolved around broken manifesto pledges and a government in disarray.

The budget was mired in controversy over the decision to raise national insurance contributions for the self-employed, a breach of the 2015 Conservative manifesto so obvious that it beggars belief that no one in the cabinet spotted it and that the prime minister and chancellor chose to plough ahead anyway.

Then, only a week later, the chancellor abandoned the plan, forced into a humiliating U-turn that created a black hole at the heart of his budget.

It looks like we will hear the same story on funding for schools.

The 2015 Conservative manifesto was unequivocal on this issue. It promised that “under a future Conservative government the amount