The former president of the UN climate summit in Glasgow, who was sacked by the Government last week, has launched a blistering attack on Boris Johnson's record on tackling climate change.

Former clean growth minister and Devizes MP Claire Perry O'Neill spoke out as the prime minister prepared to outline new measures including a ban on sales of new petrol and diesel vehicles being brought forward to 2035.

In a letter to Mr Johnson published by the Financial Times, Ms O'Neill told the prime minister: "You promised to 'lead from the front' and asked me what was needed: 'money, people, just tell us!' Sadly these promises are not close to being met."

She added: "This isn't a pretty place to be and we owe the world a lot better."

She said the PM had not convened the cabinet subcommittee on climate change that he had promised adding that the Government was "miles off track" in setting a positive agenda for the summit in Glasgow and that promises of action "are not close to being met".

Her attack came as Mr Johnson was about to outline plans for the COP26 summit, to take place in Glasgow in November in the UK, with a speech setting out Britain's stall as a leader on tackling climate change.

In his speech on Tuesday he will urge other countries to follow the UK's lead in setting targets to cut their emissions to net zero - with major cuts to greenhouse gases and any remaining pollution offset by measures such as planting trees.