Construction of a partially built new airport for Mexico City is to be halted after it was rejected in a referendum, President-elect Andres Manuel López Obrador has said.
Mr López Obrador, who takes office in December, said money would be used instead to improve existing facilities.
He has been a strong critic of the project which he says is bad for the environment and tainted by corruption.
The referendum was one of Mr López Obrador's campaign promises.
About one million people took part in the vote over four days, about 1% of the electorate, and critics have alleged cases of people casting multiple ballots.
The estimated cost of the new airport at Texcoco, north-east of the capital, has been put at more than $13bn (£10bn).
The government of outgoing President Enrique Pena Nieto says it would create up to 450,000 jobs and business leaders have insisted the new facility is needed to ease traffic at Mexico City's aging main airport.
But Mr López Obrador said that the current international airport would instead be upgraded and two runways would be added at a military airfield south of the city. He said another airport, at Toluca, would be repurposed.
"The decision is to obey the mandate of the citizens," he told reporters.
It is unclear what will happen to the site at Texcoco where the foundations for the airport have already been built.
Peter Cerda, regional vice-president for the International Air Transport Association (IATA), said abandoning the project would cost Mexico's economy $20bn annually.
"The decision puts Mexico at a disadvantage as a regional hub," he said, adding that IATA would lobby the Mexican government to change its position.
Left-wing leader Mr López Obrador won the presidential election by a landslide in July.