Trains around France are grinding to a stop as unions stage a mass strike to challenge President Emmanuel Macron's strategy for making his country more economically competitive.

Passengers are sharing cars or canceling trips after national railway SNCF said the strike will halt 85 percent of France's high-speed trains and 75 percent of regional trains.

The walkout — which started Monday evening and is to last through Wednesday morning — is also reducing train traffic on the Eurostar to Britain and trains to Germany.

French unions plan strikes two days every week through June to protest government plans to eliminate some rail worker benefits — part of broader European plans to open national railways to competition.

A quarter of Air France flights will be grounded Tuesday by a separate strike over pay.