Passenger costs at Heathrow Airport could be increased as a result of Rachel Reeves' plan to build a third runway, an expert has warned.

Clive Wratten, CEO of the Business Travel Association (BTA), said the Chancellor's ambition must not come at the expense of passengers – many of whom are travelling for work.

He added: "Many UK businesses are already face rising costs and increased operational overheads.

"It is crucial that any investment in Heathrow is managed responsibly, ensuring that improvements are not simply passed down through increased passenger charges.

"The BTA urges a clear and fair cost strategy that protects travellers while delivering the modernised infrastructure Britain desperately needs. We look forward to working with Heathrow, airlines, hotels and wider industry stakeholders to ensure that the expansion strengthens the UK’s global connectivity without creating unnecessary financial burdens for those who rely on it.”

When asked what fees could rise, a spokesperson for the BTA noted a recent increase in drop-off fees as "just one case in point".

In a letter to Heathrow, the organisation predicted that the airport’s additional revenue for parking would exceed £35.2million this the year – a number that reportedly accounts for only a 50% use of the drop-off option by drivers.

The Heathrow Reimagined campaign group has also claimed that the airport is the most expensive in the world, with customers paying £1.1billion more than if charges were in line with equivalent major European airports.

A £6 charge applies every time a vehicle enters the terminal drop-off areas at Heathrow. These are located outside each terminal.

On Tuesday, Heathrow Airport announced a new multibillion-pound investment programme to expand, including new terminal buildings, aircraft stands, passenger infrastructure and work towards its third runway.

Officials say this will include a boost to UK steel jobs. But Paul McGuinness, Chair of the No 3rd Runway Coalition, has suggested that the "expensive" project won't be a "quick fix" for the economy.

He said that any construction or purchase of steel "would be at least over half a decade away", and the project "may yet prove uninvestable as several of Heathrow’s airline customers have averred".

Mr McGuinness added: "After all, the costs of demolishing villages, diverting roads and rivers and tunnelling over the M25’s busiest junction, to increase Heathrow’s size by an area that is larger than Birmingham International Airport, promises to be inordinately expensive."

The campaigner described the announcement as "almost Orwellian", and claimed that the project’s maximum economic benefit to the UK would be somewhere between £3.3billion and minus £2.2billion over 60 years.

Regarding the increase in drop off charges, a spokesperson for Heathrow Airport told our sister site MyLondon that the Drop-off Charge is an important part of its sustainability strategy and "changes behaviour to reduce Heathrow’s environmental impact".

This reduces pollution and congestion, officials added, and free drop-off and pick-up options remain available for all terminals and long stay car parks.