French prosecutors who accuse Ryanair (RYA.I) of employing French-based staff on Irish contracts said on Friday the low-cost airline should be fined the market value of four aircraft if it is found guilty of breaking labor laws.

They say the airline infringed French employment rules in its contracts with 127 staff at Marseille airport in southern France between 2007 and 2010, and say it was a ruse to avoid paying its fair share of social security and tax.

A Ryanair spokesman said the airline does not comment on pending legal matters.

The prosecutors asked a court in the southern French town of Aix-en-Provence to fine the Irish carrier the price of four Boeing (BA.N) 737 jets. They said those were the aircraft it operated from the airport at the time.

The payment would be in addition to a fine of up to 225,000 euros ($293,700) if Ryanair is found guilty.

According to Boeing's website, market prices for its 737 jets range from $74.8 million to $107.3 million depending on the model. ($1 = 0.7660 euros)