DALLAS — London Heathrow Airport’s (LHR) ambitions for a third runway have come under scrutiny as S&P Global issues a stark financial warning.
The credit ratings agency said the £20–25 billion expansion could significantly increase the airport’s debt burden, which already stands close to £20 billion.

Major Expansion, Major Financial Risk

According to The Telegraph, S&P cautioned that the project, without robust shareholder equity, could put Heathrow at financial risk.
The agency emphasized that LHR’s debt ratings leave little room for further large-scale borrowing.

Higher Costs May Threaten Competitiveness

The report also warns that the runway project could raise already high passenger charges. LHR currently ranks among the most expensive major airports in Europe.

S&P noted that rising charges may damage the airport’s competitive position among rival European hubs. If airlines and travelers seek cheaper alternatives, this could undermine LHR’s standing as a global gateway.

Support Remains, But Questions Linger

London Heathrow maintains that the third runway will be privately funded, requiring no taxpayer contribution. The airport’s primary backers include Ardian (France), the Qatar Investment Authority, and Saudi Arabia’s Public Investment Fund.

Chief Executive Thomas Woldbye argues the expansion will ease congestion and drive down airfares by boosting flight capacity.

If approved, the runway could help increase annual passenger throughput from 80 million to 140 million by 2035.