Fiat unions say an announcement concerning the future of the Pomigliano d'Arco plant near Naples, could happen as early as Monday following this week's referendum on working conditions.

Any Fiat move - which could come on either Monday or Tuesday according to the FIOM union - comes hard on the heels of the vote which saw 62% of the workforce vote in favour of Fiat's deal and 36% against.

Fiat wants its unions on side before potentially committing to a EUR700m (US$860m) investment at the plant that could see Panda production transfer from Poland to Italy.

However, it appears FIOM is still holding out for amendments to the deal, which it says are vindicated by the 36% of workers who voted against the agreement, "numbers [which] can be considered as high," according to the labour organisation.

"FIOM says the company must reflect and think about what has happened," a FIOM spokesman in Italy told just-auto. "They must understand the workers want to work.

"The company's mistake was to put jobs against strikes - we think workers' rights and production must go together."

FIOM is agreeing with the CGIL confederation of unions which has apparently called for first day of sickness payments and strike rights to be respected, according to the FIOM spokesman.

FIOM added Fiat CEO Sergio Marchionne had now flown to Detroit but that he could make a statement on either Monday or Tuesday about Pomigliano d'Arco.

Earlier this week, Fiat issued a statement that offered no real clues as to its next move, although it clearly expressed its frustration at some unions.

"Fiat accepts that it is impossible to find common ground with those parties blocking plans for the relaunch of Pomigliano, whose arguments, in its view, are merely a pretext," it said.

"The company will work with those trade union organisations that have accepted the agreement to jointly identify and implement the conditions necessary for the realisation of future projects."

Sources familiar with Fiat in Italy indicated to just-auto the 62% in favour of the deal might not be enough.

The FIOM spokesman added that two days ago one of its representatives had been told by an unnamed Fiat plant manager that the union was important to the manufacturer.

"This does not happen every day," said the spokesman.