Shell has become the second energy major to say the UK's new windfall tax creates uncertainty about investing in oil and gas in the North Sea.
The levy - announced by Chancellor Rishi Sunak is expected to raise £5billion in 12 months, but it may run until the end of 2025 - meaning the total cost of the raid on company profits could exceed £17.5billion if hydrocarbon prices remain high over the three and a half years.
The measure will see oil and gas firms pay a 25% levy on profits - but get tax breaks worth 91p for every £1 invested, according to the Treasury.
However, Shell has now joined BP in raising concerns about the duration of the tax.
A Shell spokesperson said: “We understand the worry for millions of people about how high energy costs are challenging their household budgets – and the need for support to help make ends meet.
"But at the same time, we must sustain investment in securing supplies of oil and gas the UK needs today, while allocating future spend for the low carbon energies we want to build for the future.
"However, in its current form the levy creates uncertainty about the investment climate for North Sea oil and gas for the coming years. And, longer term, the proposed tax reliefs for investment don’t extend to the renewable energy system we want to drive forward in the UK and invest in very substantially.
"When making plans for the next decade and beyond, we need certainty.”
Shell's rival BP had previously said plans to invest £18bn across UK energy this decade would be unaffected by a windfall tax.
On Thursday it said it would review how the new regime would affect its North Sea plans. The tax was not a “one-off” but a “multi-year proposal,” it said.
Analysts estimate it will add $100million (£79million) to BP’s tax bill this year and $800million next year. The company made £5billion in profits over the latest quarter.
Louise Kingham, UK head of country and senior vice president for Europe at BP, told the Telegraph that companies need a stable tax regime.
She said: “The best way to get investment is to have stable fiscal regimes, stable environments in which to make those key decisions to bring investment forward.
“This is our home, we're committed to Britain, we've said that we're backing Britain. And we've also been really clear and said that's not somehow contingent on whether or not there's a windfall tax.
“But in a stable environment, that's a great place to put your money down. In a less stable one - you have to factor that in. And we have said we don't think that's helpful.”