Britain's 78% tax rate hollows out North Sea as Norway reopens fields and eyes Arctic drilling
UK fiscal terms are deterring investment while Norway approves three gas field restarts and presses the EU to lift its Arctic drilling ban.
ICE Brent crude front-month eased 0.34% to $86.19 a barrel on Tuesday (2026-07-28), an unremarkable session arriving as Britain and Norway continue moving in opposite directions on North Sea supply. Britain is taxing its remaining oil and gas output at 78% — among the highest effective rates in the world — while Oslo has approved development plans for three gas fields and is actively lobbying the European Union to scrap its moratorium on Arctic drilling.2,1
That 78% rate is suppressing investment at a moment when European supply margins are tight. The Treasury's windfall tax, layered on top of the existing ring-fence regime, means new capital committed to the UK continental shelf must clear a punishing hurdle before any return flows back to operators. Without North Sea revenues — which peaked at 3% of GDP in the mid-1980s — the tax cuts that defined the Thatcher era might never have happened, as The Economist noted in May (2026-05-17). High operating costs combined with a 78% government take mean the marginal barrel stays in the ground.2
Analysis commissioned by the Aberdeen & Grampian Chamber of Commerce suggests proposed North Sea developments could unlock the equivalent of 1.1 billion barrels of oil and gas by 2030, but that estimate assumes the fiscal terms become workable enough for operators to commit capital.6 The UK added another layer of pressure on Thursday (2026-05-21), when the Treasury announced it was closing a tax structure that had allowed multinational energy firms to sharply reduce their bills on North Sea profits.3
Norway is heading in the opposite direction. Its energy ministry approved development plans on Tuesday (2026-05-19) for three southern North Sea gas fields — Albuskjell, Vest Ekofisk and Tommeliten Gamma — shut for three decades. Operator ConocoPhillips told Montel that production should start in the fourth quarter of 2028, at a daily rate of 5.7 million cubic metres, roughly 1.5% of average EU daily gas consumption.1
The three fields together hold an estimated 90-120 million barrels of oil equivalent, mainly gas and condensate, equivalent to approximately 150-211 TWh, with total investment of around EUR 1.8 billion, the ministry said. Measured against Europe's overall gas demand, those volumes are modest. But they signal an active commitment to supply growth that stands apart from the UK's direction.1
Norway is pushing further. By Friday (2026-05-29), Norwegian politicians and civil servants were campaigning openly for the EU to withdraw its ban on new Arctic drilling, arguing that resources in the High North are essential to European energy security. The Barents Sea holds close to two-thirds of Norway's petroleum resources, and Oslo views the Arctic as the natural successor province to its aging southern fields.5,7
Any incremental Norwegian pipeline gas reaching the continent would push the ICE Endex TTF front-month lower — the contract held flat at EUR 58.23 a megawatt-hour on Tuesday (2026-07-28) — and by extension weigh on UK NBP day-ahead prices. A successful Arctic campaign could extend that pressure further out the curve. The EU has given no signal it intends to reverse its position.7,1
Equinor and Aker BP reinforced the Norwegian expansion thesis on Friday (2026-05-22), executing a collaboration agreement that includes an exchange of stakes in both the North Sea and the Barents Sea, Rigzone reported. The deal positions both operators for sustained activity across the full Norwegian continental shelf rather than a managed wind-down.4
Back in the UK, the trajectory runs the other way. The 78% effective rate is, by The Economist's account from May (2026-05-17), among the highest in the world. Production costs in the basin are already elevated. Those two factors together make it hard for any operator to justify new development capital, regardless of where ICE Brent crude front-month trades.2
UK output will decline. The pace matters for North Sea supply balances and, through pipeline interconnectors, for NBP day-ahead pricing into winter 2027. ConocoPhillips's Q4 2028 start date for the three Norwegian fields is the clearest fixed point in the forward supply picture. EU willingness to lift the Arctic drilling ban remains unresolved, with Brussels having given Oslo no encouraging signals yet.1,5