Energy Secretary Ed Miliband has said the government will “double down” on its environmental agenda and accused opponents of the move to net zero of “making up nonsense and lies”.

Political opponents in the Conservatives and Reform UK – and some trade unions – have argued that his agenda is putting jobs in traditional industries at risk and have urged a change of course.

The UK is legally committed to moving to net zero carbon emissions by 2050 – a goal set under a previous Conservative government.

Writing in the Observer, Miliband warned that an anti-net zero agenda would not only risk “climate breakdown” but “forfeit the clean energy jobs of the future”.

A green power transition will help secure social justice and national security, Miliband argued.

He said that the UK’s reliance on fossil fuels meant “markets went into meltdown and prices rocketed” after Russia waged its full-scale invasion of Ukraine in 2022.

“The cost of living impacts caused back then still stalk families today,” he said.

“So the argument for the clean energy transition is not just the traditional climate case but the social justice case too – it is working people who pay the greatest price for our energy insecurity.”

On his opponents, he said there are “siren voices that want to knock us off course” and added “they will also make up any old nonsense and lies to pursue their ideological agenda”.

Despite her party committing to net zero while in government, current Tory leader Kemi Badenoch has said this cannot be achieved without potentially bankrupting the country.

Reform UK leader Nigel Farage, who has criticised what he calls “net-zero lunacy”, told the Sun on Sunday that the policy could become “the next Brexit – where Parliament is so hopelessly out of touch with the country”.

Miliband has been concerned that his green policies will be blamed for the well-publicised difficulties at British Steel.

The government passed an emergency law to take control of British Steel amid accusations that its Chinese-owner Jingye was planning to switch the furnaces off.

Beijing has accused the government of “politicising trade co-operation” and said this situation had raised doubts about Chinese investment in the UK.

Parts of the labour movement, including unions such as the GMB and Unite, have warned of risks to thousands of well-paid jobs in the oil and gas sector.

But Miliband has attempted to reassure them by declaring that green energy generation will provide the good unionised jobs of the future.