Workers in Greece kicked off a day-long strike on Thursday in protest against the government’s plans for an overhaul of labour laws.

According to unions, the government’s plans will impact workers’ rights and permit firms to impose longer working hours.

The strike action by Greece’s largest private and public sector unions brought public transport to a standstill and ferries remained in ports.

A number of protests were planned to congregate in the centre of Athens later in the day, Reuters reports.

"It won't pass," said public sector union ADEDY.

When the bill was unveiled in May, Greek Prime Minister Kyriakos Mitsotakis said the measures would reform "antiquated" laws going back decades.

The government stated the reforms would provide workers with greater flexibility to set their own work schedules, and help with unpaid overtime and undeclared work, as well as tackle exploitation, the report goes on to add.

The most controversial part of the proposed bill permits employees to work up to 10 hours on one day and less on another.

Unions are concerned this will allow employees to force staff to work longer hours.

The bill is due to be voted on next week.

In addition, the move would include the introduction of a "digital work card" to track employees’ working hours in real time, in addition to increasing legal overtime to 150 hours a year.

According to critics, the government is looking to hike the eight-hour working day to 10 hours, and abandon the five-day working week and collective bargaining agreements. In addition, it will also be more difficult to initiate strike action.

Greece’s left-wing Syriza party stated the bill was a "monstrosity" and urged the government to withdraw it.

"They will not take us back to the 19th century," Syriza said.