The Treasury has borrowed more than forecast so far this year, official figures show, raising pressure on Rachel Reeves as she seeks to fill a gaping hole in the public finances.

Public sector net borrowing has hit £83.8bn since April, according to the Office for National Statistics (ONS), having jumped by another £18bn in August.

It was the highest August figure for five years and leaves borrowing so far this financial year £11.4bn above the £72.4bn that had been projected by the Office for Budget Responsibility (OBR) in March.

The rise in borrowing comes as economists believe the Chancellor will have to raise taxes by at least £20bn during her Budget on Nov 26, a little over a year after she put up levies on the nation by £40bn.

The Government has spent £36.8bn more so far this financial year than in the same five-month period a year ago, with rising public spending and debt costs outstripping the receipts from Ms Reeves’s tax raid.