The leaders of the world’s biggest green energy companies have promised more than £24bn of new private investment across Great Britain ahead of a meeting with the prime minister on Friday.

Keir Starmer is expected to meet the green energy bosses on the sidelines of the first Council of Nations and Regions in Edinburgh to discuss the multibillion-pound projects just days before the government’s international investment summit next week.

Starmer said the tidal wave of private sector spending was “a huge vote of confidence” in the government’s “relentless focus to drive growth across the UK”, which would create thousands of jobs in the UK’s nations and regions.

“Whether you’re in Scotland, Wales, Northern Ireland or England – we are creating the conditions for businesses to thrive, and our international investment summit will be a springboard for every part of the UK to be an engine of innovation and investment,” he said.

Labour ministers are under pressure to show they can fund ambitious plans for economic growth, which includes the election manifesto pledge to create a zero-carbon electricity system by 2030. The government is expected to rely heavily on private sector investment to reach its clean energy target after slashing plans to spend £28bn a year on decarbonising Britain’s energy.

The single largest investment set out ahead of the investment meeting was by the owner of Scottish Power, Spain’s Iberdrola, which has promised to double its planned investments in the UK’s clean energy ambitions to reach £24bn over the next four years.

Europe’s largest electricity company set out plans last year to invest £12bn in the UK before 2028 to rewire Britain’s ageing power grids, and build new renewable energy projects. But on Thursday it added a further £12bn to the investment plan over the same period after winning a government contract to build a new multibillion-pound offshore windfarm and agreeing to buy Electricity North West for just over £4bn.

Iberdrola’s green energy spending spree marks a threefold increase in the company’s average annual investment over the last 15 years. José Ignacio Sánchez Galán, executive chair of Iberdrola, credited the UK’s stable investment environment and “clear policy direction” towards its net zero climate goals for the investment boost.

Danish company Ørsted has also committed to spending £8bn on offshore wind alongside Greenvolt, which plans to spend £2.5bn on its planned offshore windfarms.

Mads Nipper, the chief executive of Ørsted, said: “The reason we are investing in the UK is that alongside the targets for clean energy, we also see the commitment to creating the policy frameworks required to deliver those targets and a government who wants to work with businesses to enable the investments required.”

Other investments set out on Thursday include £1.3bn from Australian infrastructure investment bank Macquarie into its Island Green Power solar farm in Stow, in Norfolk, and ultrafast electric car charging points.

In addition, US nuclear engineering firm Holtec pledged to invest £325m in a new factory in South Yorkshire to supply materials to the Hinkley Point C and the planned Sizewell C nuclear power plants which will create 1,200 jobs over 20 years.

There was also a £300m investment set out by BW Group for a new battery energy storage project in Birmingham and a £225m investment from offshore wind foundation maker SeAH Wind into its manufacturing base in Teesside which is expected to create 750 jobs by 2027.