The Treasury will get £12.5 billion more in revenues from freezing income tax thresholds than originally thought, analysis revealed on Wednesday, fuelling Tory calls for a tax cut.

Rishi Sunak, the Chancellor, had originally been expected to pull in £8 billion by stopping the point at which people start paying a higher tax rate increasing in line with prices.

But as a result of soaring inflation, pushed up by easing of Covid restrictions and global instability after Russia’s invasion of Ukraine, that is expected to now be almost £23 billion.

The analysis, produced by the leading economic think tank the Institute of Fiscal Studies, comes just as Mr Sunak is resisting calls for a tax cut in his Spring Statement next week.

Tory MPs privately and publicly have in recent months been lobbying Downing Street to delay or scrap entirely the increase in National Insurance coming next month.

Funds needed to clear NHS backlog

Both Boris Johnson and Mr Sunak are holding firm despite the Tory pressure, insisting the increase must go ahead to pay for the extra £12 billion a year needed to help clear NHS backlogs.

On Wednesday it was noted that the increase in income tax take – an estimated £12.5 billion – would cover the black hole in NHS finance that emerges should the National Insurance hike be cancelled.