The Conservatives are facing a debate over Heathrow expansion after the party's national leadership backed plans to build a third runway at the west London airport.

Shadow Chancellor Andrew Griffith is expected to say at the Conservative Party conference that a future Conservative government would do “whatever it takes” to deliver the third runway, arguing that Heathrow expansion is important for Britain's infrastructure and economic growth.

But the issue has also exposed different views among politicians seeking to become the Conservative candidate for Mayor of London in 2028.

Sir James Cleverly, one of the leading candidates for the nomination, has indicated support for the proposed runway, although he has also said that local communities should benefit from the expansion.

Other candidates are competing for the Conservative nomination, including businessman Alex Challoner and former police commissioner Festus Akinbusoye. The party's selection process is expected to narrow the field before members choose their candidate later this year.

The proposed Heathrow expansion is expected to cost around £49 billion and could eventually increase the airport's capacity to as many as 150 million passengers a year. Heathrow is aiming to secure planning approval by 2029, with the additional runway not expected to become operational until 2039.

The project remains controversial in London. Mayor Sadiq Khan has consistently opposed a third runway, citing concerns over environmental impacts, public health and pressure on London's already busy transport network.

The disagreement puts Heathrow expansion among the issues likely to feature prominently in the Conservative contest for the 2028 London mayoral nomination, particularly because the airport is located in west London and its expansion would have consequences for surrounding communities and London's transport infrastructure.

The final Conservative candidate has not yet been selected, and the positions of individual contenders may continue to develop as the selection process progresses.