Loophole could let North Sea oil and gas giants slash UK windfall tax bill

Critics warn chancellor Rishi Sunak will raise only a fraction of planned 5bn if firms offset new investment against profits

North Sea oil and gas companies that already benefit from huge tax breaks could use fresh rules to slash how much they pay under a new windfall tax announced by Rishi Sunak as part of his 15bn cost of living package, according to a thinktank.

The chancellor risks raising a fraction of the 5bn he expects from the complex scheme - which allows the cost of new investments to be offset against profits - should oil and gas companies take the opportunity to dramatically reduce their contribution to the exchequer, said the left of centre Common Wealth.