This time nothing was left to chance. As he walked between the stands of farming produce yesterday, admired the prize bulls, stroked the noses of calves, nibbled a stick of cheese, Nicolas Sarkozy was followed not just by his minister of agriculture and security detail but by a group of well co-ordinated fans bellowing support. "Nicolas, Nicolas," they shouted as the diminutive president forged ahead through a chaos of outstretched hands, moustaches and oversized animals.

The care taken by the presidential staff to ensure an incident-free visit to the annual Farm Fair in southern Paris was due to more than a well-known preference for bling over bovines. Last year the fair saw one of Sarkozy's worst gaffes when he was filmed by an amateur telling a heckler: "Casse-toi, pauvre con" (roughly "get lost, loser"). Farmers are as anxious and angry as everyone else in the country and such a confrontation, eminently likely, could not be risked again.

Already the hyperactive French president's poll ratings, 36%, are at their lowest since he was elected nearly two years ago. "Sarkozy is playing with fire ... Can he prevent the explosion?" L'Express magazine is asking on its front cover this weekend.

Last week that explosion almost came. The country's worst violence since the riots of 2005 saw youths burning cars and charging police night after night. This time the riots were not in the rundown estates that surround many French cities but in the poverty-stricken alleys of Pointe-à-Pitre, on the Caribbean island of Guadeloupe, where per capita income is half that of mainland France and the unemployment rate three times higher.

The violence resonated with a tense and angry public in France itself. The 430,000 people of Guadeloupe are theoretically citizens of the republic like those of Lille, Lyon or Paris and, though many of the roots of the protests lie deep in the colonial past, the slogans and demands of the rioters were very contemporary, focusing on pouvoir d'achat, the famous lack of buying power in the face of high prices and stagnant wages that is the main grievance of all the French.

"Looking at Guadeloupe is like looking at France through a distorting magnifying glass," said Frédéric Dabi, public opinion specialist at pollsters Ifop. "There are things that are specific to Guadeloupe, and there is a sea between over there and France, but there are all the ingredients everywhere for a wave of social panic."

In an Ifop poll for regional newspaper Sud-Ouest last week, 63% of respondents thought similar violence could soon take place on the mainland - a view shared by their leaders. All eyes are now on the general strike planned for next month. An earlier strike and mass demonstration in January was widely supported and seen as a major shot across the bows of the rightwing Sarkozy.

Though trouble in the universities remains limited - French police on Friday removed students who briefly occupied the Sorbonne as part of a long-running dispute over the president's reform plans and perceived contempt for academics - it is nonetheless seen as "warning signs before the storm", according to one French parliamentarian.

In the face of recent protests in schools, ministers backed down from major reforms. "There's the feeling that Sarkozy has a bit too much on his plate," said Jean-Baptiste Prévost, president of France's biggest student union.

For Denis Muzet, a media and public opinion analyst in Paris, all Sarkozy's talk of "reform", the very slogans that got him elected, now scares people. "Even in September, when he spoke of accelerating reforms, it was only the left who worried. When he says it now, everyone is worried," said Muzet.

An indication of the tense atmosphere came when Sarkozy's closest friend said that anyone who didn't own a Rolex watch by the age of 50 was "a failure". The remark, by millionaire advertising tycoon Jacques Séguéla, caused outrage. One French news website called it "obscene", adding it they would like to shove Séguéla's Rolex down his throat. The daily France-Soir said that "in a global financial crisis [where] people are struggling to make ends meet ... most workers will find this highly offensive".

This weekend a fragile calm had been restored to Guadeloupe, the Caribbean island system that was annexed to the kingdom of France in 1674. Last week saw the fatal shooting of a union official in rioting and street battles so bad that 260 specialist police had to be flown in from France to flood the island with forces of order, in the words of the French minister of the interior. Tourists at the many luxury hotels that support the otherwise moribund economy in Guadeloupe fled and flights were cancelled when the airport was temporarily shut.

Despite Sarkozy's offer last week of measures worth €580m (£510m) to help France's overseas regions, including aid to poor families, relief from social security contributions and price controls, there was still discontent among the protesters, who have organised a general strike that has now lasted for nearly a month. "There is nothing new in Nicolas Sarkozy's announcement. It's still far from what we are demanding, which is a €200 salary increase," said Elie Domota, the leader of Guadeloupe's mass protest movement, Liyannaj Kont Pwofitasyon (Stand Up Against Exploitation).

Negotiations between employers and the LKP, a coalition of unions and leftwing groups, were restarted on Friday but have been put on hold over the weekend. The sticking point is salaries, with bosses speaking of possible increases of between €35 and €120, depending on the sector.

The unrest has highlighted tensions reaching back to the colonial past of Guadeloupe, one of four overseas regions that are, as part of France, part also of the European Union. "The economy has kept the hierarchy of the 19th century, with all its flaws and injustices," said Nelly Schmidt, author and historian at the National Centre of Scientific Research. "There is a profound lack of understanding in France of its former Caribbean colonies. We know about the beaches, the palm trees and the rum and that's about it."

There is deep resentment of the economically powerful minority of béké, or white, families, often descendants of the slave-era colonists. After being abolished by revolutionary forces, slavery was bloodily reinstituted by Napoleon and only finally abolished in 1848.

"Guadeloupe has had a particularly bitter history of relations with the mainland," said Marc Semo, foreign editor of Libération newspaper. "That history has bred a tough and uncompromising claims culture."

Now the strike has spread to neighbouring Martinique and protests have broken out in French Guyana and the Indian Ocean island of Réunion. But it is the concern that the disruption on Guadeloupe might spread to the mainland that forced Sarkozy to act last week, meeting MPs from the dependencies and broadcasting a television address.

The latter was carefully timed to go out - on specialist channels for the overseas territories - after the main evening news bulletins on domestic TV had been broadcast. For the French government fears pressure to extend any pay increase deal in Guadeloupe to mainland France.

Last week, as Sarkozy met senior national union leaders in a social mini-summit, senior figures from the French hard left, such as the self-styled peasant leader José Bové, and the postman head of a popular new French Communist party, Olivier Besancenot, travelled to Guadeloupe. "Their fight is our fight - against capitalism, exploitation, the big supermarkets who make so much profit from us," said Anne Bronnec, 32, a shopworker handing out leaflets in the Bastille district of Paris.

Many analysts speak of a loss of direction at the highest levels of the French state. For Dabi, the pollster, Sarkozy is suffering the same fate as other European leaders who are trying to convince disoriented populations that they have an answer to the financial crisis. "There is a sense of incoherence and a sense that Sarkozy does not really know where he is taking France. But that's largely because there is an incoherence and Sarkozy doesn't know where he is taking France," Dabi said.

Last week Sarkozy unveiled proposals for tax breaks and social benefits he said were worth up to €2.65bn (£2.3bn) but ruled out raising the minimum wage or reversing key reforms such as plans to cut thousands of public sector posts. "We will beat the crisis through modernising France," the president said in a 10-minute televised speech. However, massive aid for ailing car manufacturers has already been agreed.

The nightmare scenario is that of 1995, when massive industrial action blocked the country for three weeks. The strikes at that time were led by the public sector, while this time it is the private sector that is most at risk from the looming recession. "The public sector can shut down the country, but the private sector can't," said Philippe Waechter, an economist with Nataxis Asset Management.

Equally, according to Dabi, Sarkozy has little to worry about from the left. "There are very few alternatives to Sarkozy right now. Besancenot is doing well with a message that attacks capitalism, neo-liberal economics, the rich and so on, but that's not going to cause too many problems for the president. His core support among traditional rightwing voters remains high."

For media analyst Muzet, there are two sides to the crisis: the pessimism and the worry, but also "the feeling that something is being born", a new solidarity and consciousness of the suffering of others, "in Guadeloupe today, elsewhere tomorrow".

France - whether Pointe-à-Pitre or Paris - is more divided than ever.

France in crisis

• France's economy shrank by 1.2% in the fourth quarter of last year, its sharpest decline since at least the 1970s.

• Unemployment, at 7.7% in the third quarter, is expected to soar to 9.8% this year.

• Widespread disruption is predicted. In a poll published yesterday in Le Figaro, 61% of those asked said that they expected massive strikes and social problems in the coming months, and 36% said they would welcome strikes "on a huge scale".

• "The French have huge expectations of their politicians but are not convinced [they are taking] measures which will alter the situation in any way at all," said Bruno Jeanbart, of pollsters OpinionWay.

• France's debt-to-GDP level is already set to leap to 70% this year, against a target of 66%.

• The European commission has started procedures against six European Union members, including France, for exceeding the EU's deficit-to-GDP limit of 3%.

• President Sarkozy's statement that French car-makers receiving state aid should keep production in France has alarmed other European leaders, who see it as a move towards protectionism.

• French companies' business confidence index hit a record low point in February, according to a survey from national statistics office Insee.

• Sarkozy's approval rating has plummeted to 36%, the lowest level of his presidency so far.