LIGHT from thousands of bamboo torches cuts through the gathering darkness in Tegucigalpa, Honduras’s capital. The protesters who carry them call their demonstrations marchas de las antorchas (torch marches). They have been taking place weekly at dusk since May. Their purpose: to rail against what participants see as grotesque corruption at the highest levels of government. “We can’t take it any more,” says Yelso Serna, a salesman who has marched three times.

In neighbouring Guatemala the protests, and the scandals that provoke them, are even bigger. Every Saturday since April thousands have poured into Constitution Square in Guatemala City to demand an overhaul of the political system, starting with the removal of the president, Otto Pérez Molina.

The size and stubbornness of the crowds in both countries has prompted some observers to dub the protests a “Central American spring”, like the Arab revolts that toppled corrupt Middle Eastern regimes in 2011. They draw inspiration from Brazil, where hundreds of thousands of people, enraged by a multibillion-dollar bribery scandal involving Petrobras, the state-controlled oil company, have rallied to demand the resignation of the president, Dilma Rousseff. (They are expected to do so again on August 16th.)

In Guatemala and Honduras the protests represent an “unprecedented social revolution” against a grasping political class, says Paulo de León, director of Central American Business Intelligence, a Guatemala-based consultancy. They may well bring change, but it is likely to be more gradual and peaceful than the Arab uprisings, which in most countries ended in chaos.

Rot at the top

The trigger in both countries is revelations that made corruption, long thought to be inevitable, suddenly seem intolerable. In Guatemala citizens were shocked into action by the sleuthing of the International Commission Against Impunity in Guatemala (CICIG), a United-Nations-backed team that has been investigating high-level criminality since 2007. In April this year the commission reported that officials in Guatemala’s customs agency had received millions of dollars in kickbacks in exchange for reducing import duties for companies, a scheme that Guatemalans have dubbed La Linea (the line), after a telephone hotline used by the miscreants.

The CICIG followed this up by uncovering fraud at the Social Security Institute. In July it disclosed that money from drug trafficking is financing political campaigns. Now, weeks before a presidential election on September 6th, it has alleged that the running-mate of Manuel Baldizón, the candidate who had seemed the most probable winner, used his position as head of the central bank to protect businesses that were laundering money.

The scandals, followed up by determined prosecutors, have led to a purge of top echelons of government. The heads of Guatemala’s central bank and the Social Security Institute have been arrested and three ministers have been sacked. Roxana Baldetti, Guatemala’s vice-president, resigned after investigators fingered her former private secretary as the ringleader of La Linea. Protesters are now demanding the head of Mr Pérez, although he has not been directly implicated in the scandals.

In Honduras the spark was provided by a local journalist, who revealed in May that the ruling National Party had benefited from a scheme to defraud the national health service. Hondurans have known since last year that health officials had been enjoying glitzy parties and living in mansions. Such lavish lifestyles were made possible by some $300m in bribes paid by suppliers of medicines and medical devices, which were allowed to overcharge for them. Now it transpires that shell companies involved in the scheme funnelled some of the cash to the National Party. This took place while the current president, Juan Orlando Hernández, was still Speaker of Congress.

Mr Hernández has acknowledged that his party received the money and has said it should give it back; he said he had no knowledge of the scheme. Hondurans are unimpressed. “Fuera JOH!” (“Out with JOH”), shout the protesters, referring to the president by his initials. They are demanding an anti-impunity commission like Guatemala’s.

Unlike the Arab regimes that were felled by popular anger and civil war, the Central American governments now under fire are democratic, though imperfectly so. In Guatemala Mr Pérez, a former chief of military intelligence during the government’s brutal 36-year-long war against leftist insurgents and indigenous groups, cannot run in the election in September. He will step down as president in January, if he is not pushed out first.

The scandals have enlivened the contest to succeed him. They forced the candidate of Mr Pérez’s party to drop out of the race. Now they threaten to upset the candidacy of the front-runner, Mr Baldizón, a centre-right politician with populist leanings. This month Guatemala’s supreme court stripped Mr Baldizón’s running mate of immunity from prosecution. If he is forced out, Mr Baldizón may be, too (as candidates may not run without a vice-presidential partner). That would open the field to rivals, including Jimmy Morales, a comedian, who is a political neophyte and thus untainted by scandal, and Sandra Torres, the ex-wife of a centre-left former president. In earlier times Mr Baldizón would have found a way to win despite the scandal surrounding his running-mate, says Mr De León. “But in the current climate, the outcome…is uncertain.”