UK Chancellor Rishi Sunak last night threatened North Sea energy companies with a windfall tax on their profits unless they "support the economy" by increasing investment.
He said that, unless big firms do more to protect energy security, levying a windfall tax was "something I'd look at".
The Telegraph says his comments suggest a split at the top of the Government - hours earlier, Prime Minister Boris Johnson had described the idea as a "tax on business", while Deputy Prime Minister Dominic Raab called a windfall tax "disastrous" and "damaging".
The Chancellor has previously rejected Labour proposals to levy a windfall tax on the surging profits of energy firms, buoyed by high oil and gas prices.
Treasury sources said Mr Sunak's latest comments were intended as a "warning shot" to oil and gas firms to start investing significant sums in the UK "soon".
Labour has been calling for a one-off windfall tax imposed on excess profits made by energy producers from soaring oil and gas prices.
The party has proposed a 10% increase in Corporation Tax for North Sea oil and gas firms to raise £1.2billion to help households struggling with a hike in energy bills.
Pointing to Shell's announcement last month that it will invest up to £25billion in the UK energy system in the coming years, the Chancellor said it was an "enormous investment that's great for the economy and British jobs and families".
He said he wanted more UK investment to improve energy security so the country is not reliant on importing more expensive energy from abroad, which can drive up household bills.
Mr Sunak added that he was loath to impose a tax that might choke off further investment, but warned that unless other producers followed the example of Shell he may have to impose a windfall tax.
He said: "Nothing is ever off the table in these things. Right now, what I believe is the right thing to do is to encourage these companies to invest so that we have more energy security and support the economy."
A windfall tax would be a major blow to Aberdeen, which is the oil capital of Europe, as it could badly hit sector confidence and lead to a downturn in North Sea activity.
Offshore Energies UK (OEUK) has already warned that such a move could cause irreparable damage to the industry and put consumers at risk of future supply crises.
The sector body said calls for a windfall tax offered consumers false hope - and ran the risk of damaging the country's own energy industry.
Earlier this month, the North Sea oil and gas industry received a big boost with confirmation the sector is to play a major role in Britain's plans for greater energy independence.
The UK Government's energy security strategy sets out how the country will accelerate deployment of wind, new nuclear, solar and hydrogen, whilst supporting the production of domestic oil and gas in the nearer term.
Plans include a fresh oil and gas licensing round to be launched in the autumn for North Sea projects. There will also be a new taskforce providing bespoke support to fresh developments.