Rachel Reeves is preparing to strip back environmental protections in an attempt to accelerate infrastructure building and boost the economy, according to reports.
The chancellor is considering major reforms that would make it more difficult for wildlife concerns to hold up developments, according to The Times.
Treasury officials are said to be drafting another planning reform bill, the publication reported.
The move reportedly involves tearing up parts of European environmental rules, which developers have argued slow down crucial projects.
While Labour ministers have previously insisted their current planning overhaul would balance growth with nature, Ms Reeves is understood to believe that the government must go further.
The Planning and Infrastructure Bill going through Parliament overrides existing habitat and nature protections, which, if passed, would allow developers to make general environmental improvements and pay into a nature restoration fund that improves habitats on other sites.
But Ms Reeves is considering more contentious reforms that are likely to trigger further backlash from environmental groups, according to The Times.

Among the changes under discussion are plans for a smaller, UK-only list of protected species, which would give less weight to wildlife considered rare across Europe but relatively common in Britain, The Times said.
Ms Reeves is also reportedly considering abolishing the EU “precautionary principle” that forces developers to prove projects will have no impact on protected natural sites. Instead, a new test would assess the risks and benefits of building.
The chancellor is also exploring limits on legal challenges from environmental campaigners.

Speaking to the House of Lords economic affairs committee last month, Ms Reeves said: “The reason that HS2 is not coming to my city of Leeds anymore anytime soon, is because I’m afraid, as a country, we’ve cared more about the bats than we have about the commuter times for people in Leeds and West Yorkshire, and we’ve got to change that,
“Because I care more about a young family getting on the housing ladder than I do about protecting some snails, and I care more about my energy bills and my constituents than I do about the views of people from their windows.”
High-profile examples of costly protections include the £100m Buckinghamshire “bat tunnel” built to protect wildlife from HS2 trains and the so-called “fish disco” at Hinkley Point C nuclear plant, which uses sound to deter fish from cooling system intakes.
The existing Planning and Infrastructure Bill already proposes a “nature restoration fund” under which developers could offset environmental damage by paying for conservation schemes elsewhere.
But the bill has faced criticism from both environmental groups and developers, who fear it will fail to speed up construction.
Paul Miner of the countryside charity CPRE told The Times that targeting habitats regulations would “take us backwards rather than forwards on nature recovery”.