Excerpt: Boris Johnson has admitted he went "far too fast" on net zero when he was prime minister, in his most outspoken comments against the policy he championed.

Mr Johnson said he got "carried away" by the idea that renewable energy sources could replace fossil fuels and, as a result, electricity is "too expensive for ordinary people".

He warned against "junking net zero altogether" but said Labour's target of making the UK carbon neutral by 2050 should be pushed back.

Mr Johnson makes the comments in a forthcoming book called Prosperity Through Growth, which has Tory peer Lord Elliott, founder of the TaxPayers' Alliance, and Dr Arthur Laffer, a celebrated US economist, among its co-authors.

Last week, Kemi Badenoch, the Conservative Party leader, announced plans to scrap the Climate Change Act if she becomes prime minister, which was described as a "catastrophic mistake" by Baroness May, Mr Johnson's predecessor.

It was Mr Johnson who, as prime minister, set ambitious targets for reducing carbon emissions and argued the business case for promoting wind, solar and other forms of renewable energy. He tried to get other countries to agree to legally-binding reductions in carbon dioxide emissions, which even the green lobby argued was over-ambitious.