Cristiano Ronaldo's arrival at Juventus has sparked a strike at car manufacturers Fiat.

Ronaldo's move from Real Madrid was rubberstamped on Tuesday.

Juve, Fiat Chrysler Automobiles (FCA) and CNH Industrial (CNHI) are all owned by the holding company Exor, which is controlled by the Agnelli family.

A fierce response has been seen from the Unione Sindicale di Base (USB), which declared workers at a plant in the south of the country will down tools from July 15 until July 17.

"It is unacceptable that while FCA and CNHI workers continue to make huge economic sacrifices, the company then spends hundreds of millions of euros on the purchase of a player," a statement from the USB read.

"We are told it's a difficult moment, that we need to resort to social safety nets, waiting for the launch of new models that never arrive.

"And while the workers and their families tighten their belts more and more, the company decides to invest a lot of money on a single human resource!

"Is this right? Is it normal for one person to earn millions, while thousands of families can't even get to the middle of the month?

"We are all employees of the same owner, but in this moment of enormous social difficulty this difference in treatment cannot and must not be accepted.

"The Fiat workers have made the company's fortune for at least three generations … and in return they have only ever received a life of misery.

"The company should invest in car models that guarantee the futures of thousands of people rather than enriching only one.

"That should be the objective, a company that puts the interests of their employees first. If it isn't, it's because they prefer the world of games, entertainment and everything else.

"For the reasons described, the Unione Sindacale di Base has declared a strike at FCA Melfi between 22:00 on Sunday July 15 and 06:00 on Tuesday July 17."