Economic growth is more important to the UK government than net zero, Rachel Reeves has said, dropping a heavy hint that she intends to shrug off climate concerns and reaffirm her backing for a third runway at Heathrow.

The chancellor is expected to give her firm support to the expansion of Britain’s busiest airport – as well as bringing a second runway at Gatwick into full-time use and increasing the capacity of Luton – in a speech later this month.

The climate secretary, Ed Miliband, is understood to be opposed to Heathrow expansion, and the mayor of London, Sadiq Khan, has gone public with his concerns about the plan.

But speaking to reporters at the World Economic Forum in Davos, Switzerland, Reeves appeared to dismiss such objections, repeatedly emphasising that growth, not net zero, was the government’s “No 1 mission”.

Asked about the Heathrow decision, which is expected as soon as next week, and the potential clash with the government’s climate commitments, the chancellor said: “Growth is the No 1 mission of this government, because growth underpins everything else, whether that is improving our schools and our hospitals, or indeed being able to get to net zero.”

Pressed on what she would do if forced to choose between net zero and economic growth, Reeves said: “Well, if it’s the No 1 mission, it’s obviously the most important thing.”

With gross domestic product data indicating that the economy barely grew in the latter part of 2024, the government has been stressing its pro-business credentials, believing private sector investment is the key to kickstarting growth.

Asked about how the government would meet its climate goals if it allowed air travel to significantly increase, Reeves said: “We have a commitment in statute passed by the previous government to get net zero by 2050.”

“There are lots of things that contribute to carbon emissions,” she added.

Reeves also highlighted green government projects, including investment in carbon capture and storage and the expansion of onshore wind.

The chancellor is in Davos alongside the business secretary, Jonathan Reynolds. Both are on a charm offensive to convince global businesses to invest in the UK. The pair will address scores of businesses at a lunch event on Thursday.

Reeves and Reynolds have been highlighting a series of recent pro-business decisions, including the ousting of the chair of the Competition and Markets Authority, Marcus Bokkerink, this week.

The chancellor said she believed there were too many regulators in the UK, some of whose remits duplicated others’. “I think it adds to the problems and the overlapping burdens that businesses face,” Reeves said.

She has already suggested financial regulation has gone too far after the 2008 global financial crisis.

Reeves also made clear the government was determined not to see infrastructure held up by environmental concerns.

“There’s always a reason not to invest. Always a reason not to build. You know, there’s bats and newts; it might add something to carbon emissions in 20 year’s time; it may make the view from my house a little bit less nice,” she said. “We’ll make it easier for businesses to get things done, not caught up in regulatory systems that they are stuck in for years, or planning systems with judicial review after judicial review, where you have to spend £100m to build a bat tunnel.”

A “bat shed” was built along a section of the HS2 railway line to protect a colony at a cost of more than £100m.

Reeves pointed to the fact that the government had already given the go-ahead to expansion at Stansted and City airports, which she blamed the Conservative government for failing to do sooner.

Chaitanya Kumar, the head of environment policy at the New Economics Foundation thinktank, questioned the chancellor’s apparent faith in airport expansion as a means of generating growth, however.

“Expanding our airports will not produce the economic growth that Rachel Reeves so desperately wants. The government’s plan suggests they haven’t done their homework or they would know that more airport capacity will neither bring us benefits from more business travel or money from international tourists,” he said.