IT WAS only in 2004 that Peru began to produce large amounts of natural gas, from a field at Camisea in the southern jungle which was unexploited for 20 years after its discovery. No sooner did the first gas reach Lima than the government of Alejandro Toledo signed a further contract under which a consortium led by Hunt Oil, an American firm, would build a $4 billion liquefied-natural-gas terminal at Pampa Melchorita, south of Lima, for export to Mexico. On June 10th the first shipments are due to leave, and Peru will join the club of gas-exporting nations. But far from celebrating, some Peruvians worry that what they saw as a cheap and clean source of energy for the local market will run short.

The government and the companies say that Camisea contains enough gas both to meet the export contract of 4.2 trillion cubic feet and to supply the local market for half a century. But when the separate (but overlapping) consortium which operates the main gasfield hired consultants to certify the reserves, they found just 8.8 trillion cubic feet. A new study commissioned by the government has raised that by almost 30%. Opponents remain unconvinced. They note that over 100 companies in Peru, including a new power station, are waiting to sign contracts to use the gas, but must wait for the Camisea consortium to finish expanding domestic pipelines.

A second set of objections to gas exports concerns their destination. The plant in Mexico that is supposed to receive the gas is not ready, and may not be for over a year. If Spain's Repsol, which will handle the exports, ships the gas to Asia or Argentina, it will receive a much higher price and profit than the export contract envisaged.

The most logical market is Chile. But for many Peruvians Chile's annexation of a swath of their southern territory after a 19th-century war still rankles. The government and Repsol insist that nary a puff of gas will reach Chile. But that didn't mollify mayors in towns near the Camisea fields who called a three-day protest last month. This led the government to issue a decree requiring publication of the destination of exports within 48 hours of shipments.

 Mr Toledo lays the groundwork

Peru's president, Alan García, says that investment in gas, oil and mining will total $35 billion over the next five years. So more gas may be found. Such investments have helped to turn Peru's economy into one of the most dynamic in Latin America.

But along with investment has come social conflict. Over half of the 260 protests logged by the ombudsman's office involve extractive projects. An argument over water has halted work at Tía María, a copper mine. Opposition to a proposed dam in the south-eastern jungle that would flood several villages is also fierce. Some of these protests are better-founded than others. With regional elections due in October and a presidential poll next April, many politicians will promote nationalist fears over the gas exports. That may make it harder to assess their merit.