The government is failing to provide local leaders with the investment and resources they need to achieve net zero, according to the mayor of Newham.

Rokhsana Fiaz, the first woman to become a directly elected mayor of a London borough, said her council’s “appetite [to achieve net zero] is high: we’ve got the knowhow and we know where the problems are” but, she said, the government isn’t providing local leaders with what they need.

Fiaz said that the government is “all talk” when it comes to fulfilling its promise that the country will be net zero by 2050 and will have achieved 78% reduction in emissions by 2035 compared with 1990 levels. “We get all these grand statements without any significant material resource for local government to be able to really mobilise practical measures that can help,” she said.

“One of the things that I have major problems with, with regard to the government’s talk about embracing climate emergency response, is that it’s not putting its money where its mouth is,” added Fiaz, whose Newham borough is one of the most deprived and diverse in Britain.

Johnson had claimed his government would achieve carbon neutrality by 2050 with policies such as stripping out gas boilers and switching to electric or hydrogen cars. But a Treasury review of the costs has been delayed since the spring with Rishi Sunak, the chancellor, said to be increasingly concerned that the costs would make the policy politically toxic in the “red wall” seats won by the Conservatives in December 2019.

Fiaz said the government is “basically not prepared to give us the £1 per person, per day” her borough needs to accelerate its response to the climate emergency. Instead, she said, Johnson has allowed his green agenda to be thrown into chaos by fears that the costs could play badly with working-class families in newly won Tory seats.

“This is a travesty because the working class in the UK’s most deprived communities are harmed by climate emergency more than any other [UK] people,” she said. “This is a social justice issue and the government needs to stop using the working class as a political football to kick around and a convenient excuse to not to live up to its word.”

New research by UK100, the cross-party network for locally elected leaders in the UK who have pledged to switch to 100% clean energy by 2050, has found that with the right kind of public investment, more than 2,700,000 good green jobs would be created in the move to a low carbon economy: significantly more than the 1,900,000 currently employed in the furlough scheme. Many of them will be in the manufacturing heartlands or red wall areas.

The Guardian contacted directly elected mayors from Cornwall to Edinburgh. Most called for additional central government funding and powers to enable them to achieve net zero in their communities by 2045, five years earlier than the target set by the UK government. In some cases deadlines were even earlier. In many authorities, local ambition is significantly outstripping that of the national government.

The quickest way for government to achieve net zero targets, argued Jamie Driscoll, the mayor for North of Tyne, would be by devolving funds and powers to mayoral combined authorities. “We are efficient and know how to make things happen quickly in our local areas,” he said. “We need government to match our energy and ambition … We must make government understand what levelling up really means.”

Peter Taylor, the mayor of Watford, said funding cuts made it hard for local authorities to fulfil their ambitions on climate and sustainability. “Before Covid, we saw our funding from central government cut by 70% over a 10-year period,” he said. “As a local authority we are doing everything we can to reduce the negative impact we are having on the planet but given those funding cuts from central government, we ultimately cannot do everything.”

Most of the country’s directly elected mayors have ambitious plans for their area and believe that transitioning to a green economy will be key to their success. Norma Redfearn, the mayor of North Tyneside, pointed out that “the low carbon economy is predicted to grow four times faster than the rest of the economy over the next decade, providing a wealth of opportunity”.

Reskilling will be a key part of that: retraining workers in retrofitting, or electric vehicles. Tracy Brabin, the mayor of West Yorkshire, has set up a green skills partnership and Andy Street, mayor of the West Midlands, is creating a green skills plan in order to work out how the industrial base can decarbonise.

The Bristol mayor, Marvin Rees, is calling for “new powers for local authorities to enable the transition locally, and ensure that national bodies, in the public sector or regulated industries, plan the energy transition locally – for example, to create local strategic energy bodies to do this”. His area has a wide range of green jobs, “from advanced engineering and renewables to waste management”. But in order to carry out its One City Climate Strategy – which would decarbonise the city and create 10,000 jobs – it would need an estimated £9.2bn.

And Sadiq Khan, London’s mayor, told the Guardian that the government must ensure that cities and regions within the UK are given the powers and funding to effectively support the national emission reduction targets, and to deliver the bold changes needed in their local areas. He announced London’s Green New Deal Fund last year and argues that “climate action will drive our economic recovery, create a fairer London and boost job creation efforts, rather than damage them”.

A total of 32 mayors and council leaders from across the UK recently co-signed a UK100 statement calling for a power shift from Whitehall to help local and regional authorities transition to net zero across sectors including energy, transport and the built environment. More than 60 leaders signed a second UK100 statement: the net zero pledge to go faster than central government targets.

Dan Jarvis, the mayor of South Yorkshire city region, told the Guardian: “The scale of investment is simply inadequate in relation to the threats we are facing, and the potential benefits of action.”

“The climate crisis is ultimately a much greater threat than Covid, and we are running out of time to deal with it. The pandemic – which is an economic crisis as well as a health one – should be treated as a precious opportunity to create fundamental change, rather than return to the status quo … Green investment will create jobs and boost the economy while ensuring that the massive public spending we’ll need over next few years actually produces a lasting public good.”