Two major trade unions in Italy have called for nationwide strikes over changes to the labour market, prompting huge rallies in more than 50 cities across the country.

At least 40,000 demonstrators took to the streets of Rome, protesting against Prime Minister Matteo Renzi's reforms, reported the AFP news agency.

The unions intend the rallies to be a show of anger over measures Renzi has defended as necessary to stimulate the country's moribund economy and remedy sickly public finances in line with eurozone rules.

"Today there has been an extraordinary response from workers opposed to the Renzi government's policies," Maurizio Landini, one of the best-known and most militant of Italy's union leaders, told a rally in the northern city of Genoa.

"The piazzas [city squares] are full, not just here in Genoa but in all of Italy."

The main target of Friday's strike action was the 39-year-old premier's "Jobs Act", aimed at loosening restrictions on firing employees when companies face a business downturn and weakens a treasured right to protest unlawful dismissal.

With unemployment at record levels and youth jobless rates topping 40 percent, unions say the burden of the reforms and spending cuts is being placed unfairly on workers and will do nothing to revive growth.

The strike by CGIL and UIL unions also hit public transport as well as hospitals, schools and civil administrations across Italy. More than 50 rallies were planned.

Dozens of flights were cancelled or rescheduled and there was only a minimum or partial service on most forms of public transport.

The strike and demonstrations were scheduled weeks before Renzi successfully fast-tracked the new labour market legislation through parliament, leaving Friday's events with a largely symbolic feel.

Source: Agencies