The expansion of London Luton Airport has been threatened by a government decision to call-in proposals to increase its capacity from 18m to 19m passengers a year.

An application from London Luton Airport Operations Limited (LLAOL) was approved by Luton Borough Council last year, but official consent for the growth in passenger figures was on hold subject to intervention by Secretary of State for Levelling Up, Housing and Communities Michael Gove.

LLAOL’s plans also included amending the day and night noise contours, which attracted criticism from environmental campaigners and the Conservative MP for Hitchin and Harpenden Bim Afolami.

The decision revealed in a letter to the local authority’s planning consultant David Gurtler coincides with the end of a consultation period over airport expansion to cater for 32m passengers a year.

This would depend on separate future proposals from the borough council’s airport company, Luton Rising, which would again be subject to approval by LBC’s planning committee and any potential independent review.

No date has been set for the inquiry which will be arranged by the government’s planning inspectorate, according to the letter.

It said the decision was made by the Minister of State for Housing Stuart Andrew MP on behalf of Mr Gove.

The letter said: “On the information available, the matters which the Secretary of State particularly wishes to be informed about for the purposes of his consideration of the application are: the extent to which the development is consistent with government policies for meeting the challenge of climate change, and for conserving and improving the natural environment; the extent to which it’s consistent with the development plan for the area; and any other matters the inspector considers relevant.

“The statement of case should contain the full particulars of the points which you propose to put forward at the inquiry and a list of any documents to which you intend to refer or submit as evidence.”

LLAOL received permission in 2013 to expand capacity to 18m passengers a year over a 15-year period to 2028, but reached 19m by 2019.

Campaigners welcomed the decision to allow the national planning inspectorate to review what many feel is a conflicted situation in which the council derives significant revenue from the airport, according to local protest organisation Luton and District Association for the Control of Aircraft Noise (LADACAN).

“But the local authority is also responsible for planning decisions which affect the airport’s environmental impacts on the whole local area,” explained Andrew Lambourne, from the anti-noise group.

“This is a fantastic decision. At last it’s been recognised that decisions made by LBC concerning London Luton Airport are potentially unsafe because of the clear conflict of interest.

“The airport operator agreed to planning limits knowing they were due to last until 2028, and then promptly ignored them.

“The council failed to properly monitor what was going on and, rather than enforcing these limits, invited LLAOL to apply to have them set aside, which LBC then agreed to.

“People living all around the airport had to put up with far more noise, pollution and traffic congestion than they should have between 2017 and 2019, and deserve justice.”

READ MORE: Luton Airport operator responds to calling in of expansion plans