SSE has told Chancellor Rishi Sunak that a windfall tax could put £15 billion of investment in Scotland at risk. 

Reports this morning suggest the Treasury could announce the emergency levy as soon as tomorrow, as the government desperately tries to move on from Sue Gray's report into lockdown-breaking parties in Downing Street.

Money raised would be used to fund a package of measures to help with the cost of living crisis, including a possible one-off payment for everyone on Universal Credit. 

It is not clear what the scope of the windfall tax will be, whether it will just apply to oil and gas firms, as initially touted, or if it will cover all energy providers, as briefed earlier this week. 

The warning against a change in the tax regime from SSE's chief executive Alistair Phillips-Davies came as the Perth based energy firm unveiled annual profits of £1.5billion for 2021/22, up 15 per cent year-on-year.

He told the BBC’s Good Morning Scotland that the tax could “potentially have an impact on what people are doing and what people are building.”

The energy boss said: “The key thing is this country has built enormous infrastructure and it's delivering for people in the longer term to avoid crises like this happening again. 

“If we change rules and change policies, then clearly that's going to potentially have an impact on what people are doing and what people are building. 

“If we don't have as much money to invest going forward, then that's clearly going to be an issue for us.”

Mr Phillips-Davies said he thought the Treasury would likely target oil and gas firms rather than all energy companies. 

“I don’t think this Government is going to impose a windfall tax on successful sectors that are delivering for the UK and creating jobs and making sure that we avoid these crises in the future by bringing in lower-cost energy from indigenous sources,” he told Radio 4’s Today programme.

However, former chief executive of npower Paul Massara has said he thinks a windfall tax on all energy companies is “likely”.

The former member of the committee on fuel poverty told BBC Radio 4’s Today programme: “I think the Chancellor is in a difficult situation. I think the package he put in in April wasn’t sufficient.

“We saw prices go up from £1,300 to £2,000 back in April, now £2,800, so he’s going to have to do more and it’s going to cost more, and therefore I think a windfall tax is now likely.

“The question is, where is that targeted? And I think there are some natural sectors, where you’ve seen the oil and gas sector, which have reaped exceptional rewards due to the Ukraine war and the volatility in the market, and, to me, those are the most natural areas to target this.

According to the Telegraph, Mr Sunak has concluded that the scale of profits in the sector means that a one-off windfall tax on oil and gas companies is justified.

The paper reports that the tax could be directly linked to the amount of investment each company delivers.

However, it says there was still disagreement in the cabinet yesterday on exactly who should be taxed. 

Measures reportedly being considered by the government include extra support for those on Universal Credit, including a possible inflation-linked increase.

The paper suggests the Treasury are also considering one-off cheques for some of the most in need.

SSE said their proposed investment over the next decade would equate to almost £3,000 per head of population.

The plans include investment in key technologies including new offshore wind, critical network upgrades, carbon capture and storage (CCS), batteries and hydroelectric power.

The firm is currently developing Scotland’s largest and the world’s deepest tethered offshore wind farm, Seagreen off the coast of Angus; and what will be one of Europe’s most productive onshore wind farms, Viking, on Shetland.

Earlier this year it was confirmed the business had secured rights to develop a new giant floating offshore wind farm off the coast of Angus.