By Sarah White
PARIS (Reuters) - President Emmanuel Macron, hit by a slump in popularity, faces a nationwide protest this weekend over rising fuel taxes that threatens to gridlock France's roads and show the depth of discontent with his reforms to reshape the economy.
Dubbed the "yellow vest" movement, demonstrators are threatening to block motorways and access roads to some oil depots, including in Calais near the Channel Tunnel, a major passenger and freight link into Britain.
The protest is the latest confrontation between Macron and voters in the countryside and provincial cities which view the former investment banker as the representative of an urban elite out of touch with ordinary people.
In 18 months in power, Macron has stared down muscular trade unions and street demonstrations as he liberalised labour laws and overhauled the heavily indebted state rail operator SNCF, unflinching in his resolve to bring economic and social renewal.
He has tried to shrug off accusations he is a "president of the rich", a tag milked by rivals after he scrapped a wealth tax. This time his administration - which appeared caught off guard by how fast the protest movement grew as word spread on social media - has sought to soothe poorer motorists.
"I hear the anger, and it's a fundamental right in our society to be allowed to express it," Macron said in a television interview late on Wednesday.
But he added the protest movement, embraced by Marine Le Pen of the far-right National Rally party and receiving tentative support from other parties on the left and right, had been hijacked by opponents and their supporters bent on obstructing reforms without a clear vision of their own.
The price of diesel, the most commonly used car fuel in France, at the pump increased by 20 percent in the past year to an average of 1.49 euros ($1.68)/litre, according to website http://www.carbu.com.
The higher taxes, approved in late 2017, started biting as oil prices surged in October though they have eased off somewhat since.
"WHAT DO YOU DO WITH THE DOUGH?"
Increases in taxes on gasoline and tobacco as well as an increase to a social welfare levy before other tax cuts came into force left many voters feeling Macron's reforms had eroded their purchasing power.
Their anger is reflected in opinion polls showing support for Macron falling to new lows of 21 percent.
The government is standing firm on the fuel tax hikes but on Wednesday announced a 500 million euro plan to help motorists with the lowest incomes, seeking to take the sting out of the protest movement.
The diesel tax increases are designed to encourage drivers to switch to more environmentally-friendly automobile models, part of Macron's "energy transition" plan.
But critics say that while the government hits people's wallets, it lacks a clear vision on switching to greener energy sources, citing foot-dragging by Macron's administration on reducing France's reliance on nuclear power. Rural voters are also angered by a speed limit reduction on countryside roads.
"What do you do with the dough, aside from changing the crockery at the Elysee palace or building yourselves swimming pools?" exclaimed Brittany resident Jacline Mouraud in a Facebook post viewed more than six million times.
"If that's what the money is used for, we might as well change, there's no point in you staying on."
(Reporting by Sarah White; editing by Richard Lough and Marie-Louise Gumuchian)