Pressure is mounting on UK Chancellor Jeremy Hunt for a rethink on the severity of the latest cash grab on North Sea oil and gas producers.
This month's Budget saw him hike the energy profits levy by another 10% to 35% - bringing the overall tax rate from January to an eye-watering 75%.
He has also extended the lifespan of the EPL until March 2028 from the previous date at the end of 2025.
The EPL is now expected to raise a total of £40billion - double the previous figure of £20billion. The total tax take from operators in British waters in the next six years will hit a staggering £80billion.
Tory MPs are now warning the Chancellor that the windfall levy must be watered down to avoid industry collapse.
He has been told that his so-called energy profits levy is "too blunt an instrument" in its current form and risks "destroying" North Sea production altogether.
Existential threat
The Telegraph says it comes amid warnings from companies involved in North Sea oil and gas exploration that the sheer level of taxation now poses an "existential threat" to their industry and will lead to investment becoming "unviable".
Mr Hunt and Rishi Sunak, the Prime Minister, have faced criticism that Budget did not include enough measures to spur economic growth.
MPs believe that unless a "sensible" floor price is agreed (where there would be a reduction in the level of the EPL if energy prices dipped substantially), producers firms will be "crippled" with higher taxes even when their profits fall.
Discussions are underway among rebel MPs about drafting an amendment to the Finance Bill - which is expected to be returned to parliament this week - to address this point.
Some backbenchers have written to the Chancellor to express their concern about the EPL, while others have made their disquiet clear to the chief whip.
Sir John Redwood MP told the Telegraph that the windfall levy in its current form is "excessive" and will "damage the industry" as he urged ministers to "see sense".
Another tax
"We need to get as much oil and gas out of the North Sea as possible," he said. "I don't believe it is a windfall tax if it doesn't stop when profits fall - it is just another tax on business, another tax on a business that is temporarily generating a lot of income but in the past has had heavy losses."
Craig Mackinlay MP, the chairman of Net-Zero Scrutiny Group, added: "We want more domestically derived energy. You do not get more domestically derived energy by taxing it more.
"While some of the supersize companies can accept they have had it pretty good for a while, what if those good times don't last? What happens if you have a more modest, normal profit? Are we going to still tax at 75%? It is too blunt an instrument."
Bob Seely MP said he is concerned about the security of oil and gas supply over the next decade, explaining: "We need that supply. There is no question about that. If we get this wrong and North Sea production collapses, a series of very bad things happen. For sure, we need to get tax from the industry, but we need to do so without destroying it."
A Treasury source said there are "no plans" to introduce a floor price to go alongside the EPL, adding: "We extended it to 2028 because we don't believe gas prices will return to pre-Covid levels in that time."
A Treasury spokesperson said: "We have been honest about the difficult choices we face and are asking those with more to contribute more.
"The Energy Profits Levy strikes a balance between funding cost of living support while encouraging investment in order to bolster the UK's energy security and is expected to raise just over £40billion in total over the next six years.
"We want to encourage reinvestment of the sector's profits to support the economy, jobs, and our energy security, which is why the more investment a firm makes into the UK, the less tax they will pay."