More than 120,000 new homes in England have been suspended due to the Wetlands Act

The Home Builders Federation estimates up to 120,000 new homes have been delayed due to the rules in 74 local authority areas, with 42,000 new homes delayed in Greater Norwich alone

Tens of thousands of new builds in England have been put on hold due to a Wetlands Protection Act.

Forty-two local authorities were told last month they must ensure new homes are “nutrient neutral” and don’t add harmful nitrates or phosphates to the soil in parts of the UK.

No planning permission will be granted in these areas unless developers can demonstrate that they are not contributing to nutrient pollution.

Natural England, the government’s conservation agency, has already required developers in 32 local authorities to prove they are not causing additional pollution to protected areas, following a 2018 Court of Justice ruling protecting EU-designated nature reserves.

Nutrient pollution causes algal blooms that deplete oxygen in the water, killing fish and harming aquatic life.

However, local councils say they have not been given sufficient notice to allow new developments to proceed.

The Home Builders Federation estimates up to 120,000 new homes have been delayed due to the rules in 74 local authority areas, with 42,000 new homes delayed in Greater Norwich alone.

Most areas have issued a blanket ban on building in affected areas until the ruling is overturned – a move that threatens to derail Boris Johnson’s campaign pledge to build 300,000 new homes a year.

Rosie Pearson, Chair of the Community Planning Alliance, said: “It’s great to see and a rare example of where the public protection system is doing what it should.

“But with councils bound by their five-year targets for housing supply and a government agency saying ‘build, build, build’ and then Natural England and Defra go, ‘you can’t build, you’re harming the environment’ . it’s a complete mess.

“All these wetlands are being created that are going to be great for nature, but the government keeps ignoring the underlying problem, which is the sewage system.”

Homebuilders warn the measures could cost developers up to £5,000 per house and delay affordable houses and social housing.

James Stevens, director for cities at the Home Builders Federation, said: “Developing a consistent and standardized approach to mitigating water neutrality is essential to removing the growing blockage to the home supply.

“We call on the government to immediately agree on appropriate measures that reflect the contribution of housing provision to this problem. The situation has been going on for a number of years and it is imperative that solutions are urgently agreed and implemented.”

Melanie Hughes, director of sustainable development at Natural England, said all protected wetlands affected were in an “unfavorable state” due to nutrient loading.

“We can’t keep polluting these areas — that’s the line that’s been drawn,” she said.

“We’re excited to use nature-based solutions to solve the problem, which have broader benefits.”

A government spokesman said: “We want to protect the environment and address increasing nutrient pollution as we build the homes this country needs.

“While housing is not the primary cause of nutrient build-up, we want to take action quickly to drive development forward.”