Fiat’s largest union has denounced as “illegitimate and unacceptable” an agreement signed by the automaker’s other labour representatives.

The Italian manufacturer is asking its workforce to accept a productivity improvement deal in exchange for transferring new Panda work to its Pomigliano d’Arco plant near Naples, but the FIOM union is claiming the agreement is “blackmail.”

FIOM’s ire has been provoked by Fiat explicitly linking acceptance of the productivity deal – which could see more flexible working shifts introduced – to production of the Panda model that envisages raising volume to around 300,000 units per year.

“We are against the blackmail by Fiat,” a FIOM spokesman told just-auto. “We say this because if you say yes [to the deal] the plant will go on and if you say no, the plant will close.

“We think the separate [other unions] agreement is illegitimate and unacceptable.”

Fiat is now putting its formal deal to the workforce in a referendum on 22 June, but even this has angered FIOM, although it is urging its members to vote “to avoid reprisals.”

“This is not a referendum about union actions, it is about what the company says,” added the FIOM spokesman. “But there is a big but here. The assembly [union] says to the plant workers, it will be better to vote in the referendum to avoid reprisals.”

The union will now also launch a series of wildcat strikes, although these will be walkouts of only around one hour around Fiat’s sites.

FIOM shop stewards are equally putting out a ‘solidarity’ document today (17 June) to explain the union position.

A Fiat spokeswoman confirmed four unions had signed the agreement, but that FIOM had declined to do so.