The OBR leak

Secret details revealed - 40 minutes early

- Richard Partington Jessica Elgot

Reeves checks the news on her phone as the PM speaks yesterday

Shortly before midday yesterday, a series of headlines about Rachel Reeves's budget began appearing on the Reuters newswire, sending ripples though financial markets.

The details were jaw-dropping: they appeared to spell out the key policies of the chancellor's budget more than 40 minutes before she was due to deliver them to a crowded Commons chamber.

An alert published at 11.41am, for example, read: "UK OBR ECONOMIC AND FISCAL OUTLOOK: BUDGET TAX RISES RAISE 26.1 BLN STG BY 2029-30."

In the chaotic moments that followed across newsrooms and trading floors, the Office for Budget Responsibility (OBR) appeared unaware it had published its highly sensitive analysis of Reeves's tax and spending plans in full on its website.

The Reuters snaps flowed and bond prices and sterling began moving as markets hastily executed billions of pounds of trades. The yield - in effect the interest rate - on 10-year UK government bonds initially dropped by 0.4%, while the pound jumped by 0.3% on the news that the chancellor had built a significantly larger than anticipated fiscal buffer.