The French-owned contractor suffered pretax losses of £62m in the year to December 2023, worse than the £42m loss reported in the prior year.

Bouygues UK, which carries out an array of work from schools to housing, student accommodation and healthcare projects, also reported turnover down by 15% to £326m, marking a further year of contraction from £484m peak sales in 2021.

Customer warranty provisions including building safety post-completion liabilities jumped to £116m from £62m.

The hit saw its French parent company inject £50m into the business last December, improving year-end cash levels to £188m.

In a statement released with the accounts, chief financial officer, Thibaut Roux, said: “The loss for the year arose as a result of cost increases due to subcontractor performance, availability of labour, the conflicts in the Ukraine and the Middle East as well as the continuing impact of post-completion liabilities relating to building safety.

“Subcontractors continued to be impacted during the year in regard to delivery of services as a result of challenging market conditions. There were a small number of failures of subcontractors working for the company during the year.

“Actions were implemented to ensure that works were able to continue with cost forecasts being revised accordingly.”

Average headcount at the business fell to 1916 (2022: 1957).

The accounts did not include Bouygues’ work on infrastructure schemes such as HS2 or Hinkley Point, which are being delivered through sister company Bouygues Travaux Publics and other parts of Bouygues Construction.