Households face an estimated bill of £2,300 for switching off the UK gas network as part of the government’s drive towards net zero, a leaked draft official report suggests.

The cost of decommissioning the network could reach a total of £65 billion, according to a draft report by the National Infrastructure Commission (NIC).

It is the first time a public body has examined the future of the 176,000-mile network of buried pipes, which serve eight in 10 homes but are at risk of becoming obsolete under plans to achieve net zero carbon emissions. Unused pipes must be removed or risk collapse, and experts fear possible road collapses.

Households could be left to bear the cost through higher energy bills or taxes, as there is no provision in current government budgets to remove them and energy companies are not obliged to cover the costs.

NIC did not dispute the figures when contacted, although an insider insisted it was a draft report and could change before its final release next month.

The NIC believes the grid could theoretically be converted to carry hydrogen, which is cleaner, but would also cost “tens of billions of pounds” and there are doubts about hydrogen’s suitability as a mass heating solution.

Conservatives say the figures raise serious questions about the government’s plan to reach net zero by 2050.

Craig McKinlay, the Tory MP who chairs the net zero parliamentary group, said: “Little by little, the true astronomical cost of net zero is being revealed and it is not clear whether the products we are being forced to switch to are any better than our ancestors.”

“The forced conversion from gas boilers to heat pumps seems like a good example; it will also leave the country with a vast network of redundant infrastructure that will cost tens of billions of pounds to remove.”

“I am concerned that the command and control approach to net zero that the government is taking will leave us with a cost of living crisis that stretches far into the future.”

The prospect of hydrogen heating looked “dead”, Mr McKinlay added, after Grant Shapps, the former energy minister, appeared to rule it out in July.

Sir Jacob Rees-Mogg, former business and energy minister, said the government’s net zero plans were “stuck in cloud land”.

He said: “The government cannot withdraw the gas network because it cannot afford it.”

“They need to consider very seriously whether the legal obligation to achieve net zero is realistic.”

However, Kwasi Kwarteng, another former business and energy minister, said the decommissioning costs were “hypothetical”.

He said: “Given the infrastructure we have, it doesn’t make sense to take the whole network out of service at great cost. I cannot understand the government doing this.”

“It is unrealistic to expect that all heating in this country will be electrified.

Under current proposals for households and businesses to “stop the unabated burning of natural gas”, ministers are backing electric heat pumps as the main replacement for gas boilers.

But if most households ditch their boilers, the existing gas mains cannot simply be turned off and left in the ground for safety reasons.

One industry source said: “We have large diameter pipes that cross major cities. If we just turned them off and didn’t maintain them, they would fall apart – and the roads could start to deteriorate.”

Shutting off the gas network would be a complex but gradual process as people switch to alternative technologies, requiring engineers to safely shut off certain areas while allowing gas to continue flowing elsewhere.

The ultimate fate of the network, which was privatized by Margaret Thatcher’s government in 1986, will depend on how much it is repurposed to carry hydrogen.

At least part of the network is likely to be used in the future to supply hydrogen to heavy industry, which cannot be easily decarbonized. But ministers are waiting until 2026 to decide whether hydrogen will also be used for heating houses.

Many experts “poured cold water” on that idea, pointing out that hydrogen is energy-intensive to produce and that it must be burned in much larger quantities than natural gas to produce the same amount of heat.

Meanwhile, the monopoly owners of gas networks continue to invest billions of pounds in upgrades, replacing metal pipes with plastic ones, in a program that stretches to the 2030s.

These investments will be paid for by consumers through their bills – along with any future decommissioning costs.

dr. Richard Laws, a heating expert at the University of Exeter, said the government should consider whether the upgrade program was still good value for money or would unnecessarily increase energy bills.

He also warned that as more households are switched off, those still online could be forced to bear an increasing share of decommissioning costs – increasing the risk that those who cannot afford a heat pump will be financially “trapped”.

dr. Lowes said: “It’s a big problem and nobody [in government] has a right.”

“There are basically two options: you pay through the bill or through the tax system.”

One way to ensure fair load sharing would be for the government to nationalize the network, which today is estimated at around £20 billion, he said.

An NIC spokesman said: “We do not comment on leaked reports.”

“We will publish information on the different options for the future of the gas network as part of the next National Infrastructure Assessment in October.”

A government spokesman said: “This claim is simply untrue. Our gas network will always be part of our energy system and therefore such assessments are wrong”.

“We have and always will put accessibility at the heart of our approach to improvement.” We will continue to work with industry to investigate whether the use of hydrogen offers consumers value for money and meets the necessary safety standards”.