The demonstrators departed from various points in the region, such as Grândola, Santiago do Cacém, or Vila Nova de Santo André in the latter municipality, and are circulating slowly on the roads near this industrial complex.

As they pass the refinery, drivers honk their horns and some shout slogans against the cost of fuel, under the watchful eye of military police.

The group that departed from Grândola, also in the Setúbal district, gathered in the early morning hours at a gas station on the IC1 highway, near this Alentejo town, and, at 8:10 am, set off for the refinery in a slow march.

Always accompanied by the GNR (National Republican Guard), the protesters marched with Portuguese flags on the hoods and windows of their cars, while others pasted posters that read "Enough with the fuel price increases" or "Families can't take it anymore."

"We will go to the last resort to achieve our goal, which is to change fuel prices and find a solution that is valid for everyone," Ruben Marques, a businessman and one of the organisers of the protest, told the Lusa news agency.

Arguing that fuel prices have reached unaffordable levels in Portugal, this businessman from Grândola warned that, given the constant increases, "it is impossible to survive" and the cost "has direct and indirect repercussions on everything."

"We are talking about food, gas, all kinds of medicine, all kinds of transportation, everything is influenced by fuel," he stressed.

In statements to Lusa, Ruben Marques said that the protesters are demanding from the Government “a reduction in fuel prices to a fair value in the order of 1.60 euros or 1.65 euros”.

Joining the group from Grândola were leaders and associates of APROSERPA - Association of Farmers of the Left Bank of the Guadiana, based in the municipality of Serpa, district of Beja, who are unhappy with “the brutal increase” in fuel prices.

The protest was organised through groups on the instant messaging application WhatsApp.