It is peak tourist season in Greece, and on the pristine Monastiri beach on the northern tip of Paros island, a phalanx of lounge chairs with red umbrellas covers the sand. At 70 euros for a pair of front-row seats near the crystalline waters, less than half were taken on a recent day, as Greeks and tourists alike who did not want to pay instead sheltered from the sun under nearby trees.
“In some cases they covered 100 percent of the beach,” said Nicolas Stephanou, 70, a local resident. “We feel we’re being pushed off the island,” he added, explaining that people are made to feel unwelcome unless they use the services of the beach bars that own the chairs.
Many local people like Mr. Stephanou have had enough, saying seaside businesses have left them hardly a scrap of sand on which to lay their towels. In recent weeks, hundreds of people of all ages have staged demonstrations, walking along the sand on three beaches with banners saying “Reclaim our beaches,” as part of a movement called Save Paros Beaches.
Since starting in July, the protests have caught on nationwide, inspiring a “beach towel movement” organized over social media from Corfu in the north to Crete in the south.
While beaches are public in Greece, local authorities lease sections of them to bars, restaurants and hotels. Though no more than 50 percent of a beach is supposed to be occupied, many of the businesses are expanding illegally, occupying more space than they leased.
On Paros, which sees its population of 14,000 increase by tenfold in the summer, those businesses have become predatory, residents say, charging up to 120 euros, or about $130, for “V.I.P.” sun loungers.
Tourists are not too happy about the proliferation of the chairs, either.
On the island’s Kolymbithres beach, 10 rows of lounge chairs recently occupied one sandy cove.
Vasileios Paraskevas, a 47-year-old car factory worker from Germany, said he and his wife couldn’t find room for their own umbrella. “We couldn’t go left, we couldn’t go right,” said Mr. Paraskevas, who ended up sheltering under a tree. “There was no space for us.”
On the same beach, three sisters from Australia were sunbathing on towels in a corner. “We were going to get a lounger, as we couldn’t find a free strip of sand to sit on, but they wanted 70 euros,” said Sue Slieman, a 40-year-old hospital scientist visiting with her sisters, Hoda, 42, and Laura, 37.
“Everyone should have access to the beach; it shouldn’t depend on your income,” said Hoda Slieman.
As part of their fight against the businesses’ expansion on the sand, members of the Save Paros Beaches group downloaded the contracts of businesses from an online government registry and plotted the coordinates of the areas allocated to them over aerial photos taken by drones.
“There were massive discrepancies,” Mr. Stephanou said — the 7,186 square meters leased to businesses last year ultimately expanded to 18,800 square meters. Residents collected thousands of signatures for a petition to make businesses follow the rules.
As the movement spread, the authorities reacted. In late July, inspectors descended on two beaches on Paros, and sun chairs were removed. Then, Greece’s Supreme Court prosecutor ordered an investigation into violations on Paros and the island of Serifos.
Fearing fines, some businesses removed chairs, at least temporarily. On Naxos, lounge chairs and four-poster beds that had been placed on beaches were cleared — only to reappear as soon as inspectors left. The authorities later arrested three businessmen.
Inspectors conducted more than 900 checks of Greek beaches between July 21 and Aug. 8, and penalties were imposed in a third of the cases, said Kostis Hatzidakis, the finance minister of Greece. He heralded an overhaul of the legal framework governing the concession of beaches to businesses “to make it more modern and transparent.”
The current system is anything but efficient, Markos Kovaios, the mayor of Paros, conceded in an interview.
“We have a problem,” he said, calling for the review of a law under which local authorities must defer to the ministry for approval of lease agreements with businesses and for inspections of infractions. “We should be in charge.”
As for the citizens’ movement, he said it was excessive, noting that Paros has at least 30 beaches that do not charge to use chairs. He suggested the movement might be politically motivated, since local elections are set for October.
At a local council meeting last week, however, the Paros municipality approved a set of proposals by the citizens’ movement aimed at ensuring that businesses no longer operate beyond the areas allocated to them.
Analysts said the movement expressed pent-up frustration at exploitation by businesses that are pricing Greeks out of a fundamental right.
“In a country where unbridled profiteering is rampant, Greeks are taking action to reclaim their public space,” said Seraphim Seferiades, a professor of political science and history at Panteion University in Athens. “The situation on the beaches may have been the straw that broke the camel’s back.”
Eleni Andrianopoulou, a spokeswoman for the movement on Naxos, said locals would protest “until justice is restored.”
“They shoo people away, they tell us you’re spoiling the view,” Ms. Andrianopoulou said. “It’s hugely upsetting. You go to the beach to clear your head of troubles, not fill it with anxiety.”
Some beach bars refused to comment.
It is clear, though, that lax oversight and bureaucratic delays often allow some businesses to operate with impunity. Even those businesses that receive approval to operate usually sign government contracts at the end of the season, rather than before, because of understaffing, the mayor of Paros admitted.
Giorgos Arkoulis, the owner of the Dixty restaurant, which has operated on Mikri Santa Maria beach on Paros for 28 years, was denied a license to put sun loungers on the beach this year but did so anyway. He said he was expecting the “illogical” decision to be overturned. Instead, he was forced to clear away the lounge chairs, a move that prompted complaints from his customers.
Indeed, not all visitors support the movement.
“I don’t agree with it — there’s enough space for everyone,” said Theofilos Afouxenidis, a 45-year-old accountant sitting under a tree next to the Marcello Beach Bar on the northwest coast of Paros. “I was here last year, sitting on a lounger at the front of the beach. It was great.”
Grigoris Pirpiris, a 29-year-old native of Paros who lives in Athens, said he was glad officials had forced businesses to free up space on Marcello beach, where he played as a child. But he is concerned about the type of excessive tourist development, that he said has overrun nearby Mykonos.
“They have to put the brakes on. It’s too much,” he said. “The beach is nature.”
