ROME – The head of the Italian Air Force has launched an unusually forthright attack on the Italian government’s see-sawing commitment to the F-35 program, and has claimed Rome owes Lockheed Martin €389 million ($439 million) for delivered aircraft.

Gen. Alberto Rosso told Italy’s parliament on Tuesday that he felt “strongly concerned about the uncertainty” affecting the F-35 program in Italy “and the eventual hypothesis of a drop in numbers” or orders.

“Any alternative to the F-35 would certainly be older, outdated, less efficient and more expensive aircraft,” he told a joint session of the Lower House and Senate defence committees.

Rosso’s speech followed months of ambivalence about the F-35 from Italy’s populist coalition government which took office last year.

One of the parties making up the coalition, Five Star, promised while in opposition to scrap Italy’s plan to order 90 aircraft for its air force and navy, but since taking office the new government’s defense minister — who was nominated by Five Star — has stuck with the program.

The minister, Elisabetta Trenta, has spoken of slowing down and reviewing the program, however, while the government has not confirmed the final number of aircraft it wants to buy.

On the other hand, a junior defense minister, Angelo Tofalo, who is also a member of Five Star, heaped praise on the program in December.

General Rosso said he was “worried” about the program, which he called “the future of the Italian Air Force.”

“Slow downs or reductions in numbers are extremely worrying for operational capability, for national industry and the economic benefits [the program]brings,” he said.

He also confirmed Italian press reports this week that Italy is behind on payments to Lockheed Martin for aircraft, with €389 million in bills from 2018 still to be paid.

Italy is about to take delivery of its 12th F-35, has 25 trained pilots and declared initial operating capability in November.

Italian firms are also waiting for cash to be made available by the new government for defense programs, an Italian source said. Money due to be freed up by the country’s economic development ministry by the end of January to cover 2019 spending had yet to be be allocated, said the source.

Addressing the parliamentary commissions, Rosso took the opportunity to tell lawmakers that he backed the six-year defense spending plans which were promoted by a recent defense white paper, but have yet to be introduced by law.

Current one-year budgets were preventing the armed forces from signing more-efficient, multi-year logistics contracts with industry, he said.

He also appealed for help for Italy-based Piaggio Aerospace, which was placed into receivership last year by its then-owner, UAE investment fund Mubadala, which also cancelled its order for drones from the firm.

Observers has suggested Mubadala was fed up waiting for a promised order from the Italian Air Force for drones from the firm — a delay blamed on the Italian parliament.

Rosso said that Italian state-controlled defense giant Leonardo now needed to step in to help run Piaggio Aerospace, which is currently being managed by an Italian government-appointed administrator.

Leonardo, he said, needed to be “pulled by the ears” to help the firm survive.