Labour has claimed that energy infrastructure projects cancelled or blocked under the Conservative government would have generated enough low-carbon power for more than three-quarters of British households each year.

The opposition has calculated that the potential energy from nuclear and renewables projects, which hit the buffers since the Tories won the 2015 general election, adds up to power for around 20 million homes.

It says the cancellation and suspension of plans for three major nuclear power plants over recent months has resulted in the loss of power for 17 million homes per annum.

Moorside in Cumbria was scrapped in November last year, followed by the suspension by Hitachi of its plans for the Wylfa Newydd project and Oldbury in January.

Labour’s figures also include the government’s block on onshore wind, introduced in 2015, which it claims is blocking nearly 800 shovel-ready projects that could provide enough power for more than three million homes. And the ‘world-first’ tidal lagoon power plant in Swansea Bay, which Labour says would have provided power for nearly 150,000 homes per annum.

The opposition has also accused the government of not setting concrete targets and failing to bring forward substantial new investment in order to help meet the ambition outlined in the recent offshore wind sector deal to deliver “up to” 30 gigawatts of energy by 2030.

Labour has pledged to approve the Swansea Tidal Lagoon, remove barriers to onshore wind and support new nuclear.

Rebecca Long Bailey MP, Labour’s shadow secretary of state for energy, said: “These figures show that the Tories risk failing in one of the first duties of any government – keeping the lights on.

“When the Wylfa plant was cancelled Greg Clark announced an energy white paper for summer 2019 – six months down the line. That’s the sign of a government absorbed in its own meltdown, not the real issues facing our country. Ministers should come clean to the public about the gaping hole in their plans and what that means for our energy security.

“Labour has been consistent in its support for nuclear as part of our energy mix, calling on the government to take a public stake in new nuclear projects. We would end the short-sighted and ideological Tory ban on onshore wind and mobilise huge investments in renewable energy.”