Amid the Tories’ fiscal disasters, one change has quietly warped how we see public spending for ever

The OBR’s approach ‘militates against any radical policy changes – whether those are tax cuts or big public-spending commitments’. Composite: Guardian Design/Reuters

The Treasury traces its origins back to the early 12th century. The Bank of England was established in 1694. But when Liz Truss blamed her downfall on the “leftwing economic establishment”, she singled out the Office for Budget Responsibility (OBR), set up by George Osborne in 2010, as a particular target.

And she’s far from wrong about the OBR’s influence on the policy debate. The way the political conversation about tax and spending is framed during this election owes more to the OBR and its interaction with the government’s “fiscal rules” than to either the Bank or the Treasury. So the creation of the OBR is indeed one of the most consequential economic policy decisions since 2010.