Rachel Reeves v the OBR: chancellor aims to loosen the watchdog’s grip

As tensions spilled over, Reeves used an interview to call on the OBR to ‘score’ pro-growth government policies. Photograph: Peter Byrne/PA Media

For a crew of 50-odd nerds sharing an uninspiring concrete block in Westminster with the Ministry of Justice, the Office for Budget Responsibility has come to wield extraordinary power.

It was the OBR projections of Rachel Reeves’s evaporating headroom that left the chancellor scrambling for welfare cuts in March. And it is the watchdog’s rethink about productivity growth that means the chancellor is sure to deliver a second tax-raising budget on 26 November.