Financing for Airbus's next- generation passenger jet has been thrown into doubt after the World Trade Organisation ruled that the A380 superjumbo received illegal export subsidies from European governments.

The WTO found funding from Germany, the UK and Spain for the world's largest passenger aircraft amounted to prohibited export subsidies, prompting Boeing, Airbus's US rival, to call for $4bn in loans to be repaid or restructured “without delay”.

Yesterday's report, which ran to more 1,000 pages, closes one chapter of a six-year battle between the world's two largest commercial aircraft manufacturers. The WTO is expected to issue a preliminary ruling on a companion case filed by the European Union against the US over alleged subsidies paid to Boeing in mid-July.