Farmers blocked one of France's main motorways linking Paris with the northern city of Lille, the Benelux and Britain on Friday, causing kilometres of traffic jams, the first major traffic disruption caused by the protest movement in the French capital.

Local farming unions have called for roadblocks in and around Paris on Friday to step up the pressure on the government which the farmers accuse of not helping them enough to cope with what they say are low food prices and excessive regulation.

The roadblock on the A1 north of Paris led to traffic jams of around 4 km (2.5 miles) in the morning, according to the transport ministry's online service Bison Fute.

French media reported farmers had also set up first roadblocks on traffic axes in the Essonne department south of Paris in the early morning hours, while most protests were expected to start in the early afternoon.

The government said it would announce first immediate measures aimed at taming the farmer outrage later on Friday with Prime Minister Gabriel Attal expected to speak in the afternoon.

So far, the government has not specified when and where Attal is due to speak or what measures could be announced.

(Reporting by Yves Herman, writing by Tassilo Hummel Editing by Tomasz Janowski)