A petition against Budapest's bid for the 2024 Olympics started on Thursday, with the aim of having a referendum on the issue.
The Momentum movement initiated the petition in which they need to get the support of 138,000 Budapest residents within 30 days to force the city council to hold a referendum on the Olympic bid.
Budapest is running against Los Angeles and Paris for the 2024 Games. The International Olympic Committee elects to host city in September at its session in Lima.
Momentum, a new political movement opposed to Prime Minister Viktor Orban, says the costs to host the Games would have a catastrophic effect on Hungary's economy.
For Orban's government the Olympic bid is a matter of big prestige.