London's Heathrow Airport has told unions it will seek pay cuts for thousands of workers due to the coronavirus collapse in air travel.
The airport is looking for pay cuts of 15% to 20%, affecting about half of the 4,700 staff in engineering, air-side operations and security.
It warns job cuts could be implemented if no agreement is reached.
Heathrow said in a statement that Covid-19 has decimated the industry and had cost the airport £1bn since March.
The airport has informed union officials that it was triggering a 45-day consultation period about the proposals, which involve voluntary severance schemes as well as pay and recruitment freezes and salary reductions for management.
However, the west London airport said its proposals "guarantee a job" for anyone who wants to remain with the business.
Heathrow has already reduced its managerial roles by a third, and in June launched a voluntary redundancy scheme.
"Provisional traffic figures for August show passenger numbers remain 82% down on last year and we must urgently adapt to this new reality," the company said in a statement on Wednesday.
It continued: "Discussions with our unions have taken place over four months and our final offer is informed by feedback we have received from them.
"But with air travel showing little sign of recovery, these discussions cannot go on indefinitely and we must act now to prevent our situation from worsening.
"We have now started a period of formal consultation with our unions on our offer, which still guarantees a job at the airport for anyone who wishes to stay with our business."
Wayne King, an official at the union Unite, said the plans would "further undermine confidence in the industry". It comes after airlines and tour firms announced thousands of job cuts.
Mr King added: "Our members have worked tirelessly throughout the Covid-19 pandemic. To conduct industrial relations via the media in such a brutish manner is designed to create fear and panic in a group of key workers."
He said "it should not be forgotten that Heathrow is an incredibly wealthy company", claiming that the attempt to cut pay and job was about boosting future profits.