Amid waning popularity for hosting the games, Budapest plans to drop its bid for the 2024 Summer Olympics, leaving only Paris and Los Angeles to vie for hosting duties.

Hungary’s government announced its plan to pull out of the race as public opinion turned against the prospect of hosting the massive event. A poll released Wednesday showed that half of Hungarians wanted the capital city to withdraw its bid, and on Friday, Budapest voters submitted a petition with a quarter million signatories demanding a referendum on the issue.

“For Budapest and Hungary the Olympics is a national issue,” the government said in a resolution published through the Hungarian news agency MTI. The declaration added that initial public support for the bid “had been broken.”

Critics claim that hosting the games would be too expensive: Host cities must build huge venues, provide housing for athletes, and ramp up security to protect the masses of spectators flowing into town. Costs often run into the billions and are largely footed by taxpayers.

“Doesn’t the gargantuan cost make the prestigious event a poisoned chalice?” the Budapest Times, an English-language newspaper, wrote in a 2015 story debating the expenses.

Only the International Olympic Committee (IOC) can formally withdraw a bid. The agency said it is waiting on confirmation from Hungary before it takes Budapest out of the running.

Rome dropped out of the 2024 bidding process in October, and Germany pulled its Hamburg bid in November 2015 after more than half of residents voting in a referendum opted against it.

The IOC will vote on the 2024 host city in September.

Wildly expensive despite reforms

Hosting the Olympics is no cheap feat. A 2016 study found it takes a whopping $3.1 billion on average to cover the core costs of the games.

Last summer’s Olympics in Rio de Janeiro had a price tag of $4.6 billion, according to the study, and the 2014 Winter Olympics in Sochi cost a staggering $21.9 billion — blowing Russia’s projected budget by 289 percent.

But that only covers direct expenses — building sporting arenas, Olympic villages, and broadcast centers, for example — and doesn’t include other upgrades a host city may choose to make, such as building better roads and more hotels, before it’s inundated with visitors. Those peripheral expenses can tack on millions, if not billions, of dollars.

In 2015, the IOC approved Agenda 2020, a series of Olympic reforms that, among other things, were meant to make hosting duties more affordable and add more cities and countries to the pool of potential hosts.

Under the reforms, the IOC encourages host cities to use existing facilities instead of building new ones from the ground up. The committee also now allows regions to host the games, a move that could spread the economic burden from a single city to a wider area. However, the IOC would only allow a single Olympics to cross international borders in “exceptional circumstances” — meaning that a single country is still responsible for hosting costs.

Agenda 2020 made the bidding process cheaper, too, by making the IOC foot part of the bill.

But the new rules don’t seem to be keeping more hosts in the running, as proven by the thinning 2024 crop. And it doesn’t seem like the games will get cheaper anytime soon. Experts warned the Summer 2020 Olympics in Tokyo could cost an astounding $30 billion.

And then there were two

If the IOC accepts Hungary’s plea to leave the bidding process, only Paris and Los Angeles will be left in the running.

The latest draft of California’s proposal, issued in December, estimated it would cost $5.3 billion to host the Summer Games. The bidding committee claims it will be able to cover all of that with ticket sales and funds collected from broadcasting rights and sponsorships.

“We have been extremely conservative in our approach,” Gene Sykes, the committee’s chief executive, told the Los Angeles Times.

Meanwhile, France has promised to limit its spending, should it get the 2024 games. Paris’s plan uses 70 percent existing venues and 25 percent low-cost temporary venues. The city’s infrastructural budget for the Summer Games is $4.5 billion.

Despite the conservative proposals for the two remaining bidding cities, Olympic experts said Budapest’s decision to pull out highlights an urgent need for more reforms.

“We need to take a long look at what we need to improve,” IOC member Adam Pengilly told Reuters. “Agenda 2020 has moved things forward and it needs to continue.”