By Michel Rose, Elizabeth Pineau and Crispian Balmer

Italy, Saudi Arabia and South Korea are battling it out in Paris on Tuesday for the right to host the Expo 2030 world fair, a five-yearly event that attracts millions of visitors and billions of dollars in investment.

The three countries' delegations have been in horse-trading overdrive over the past few months to win votes from the 182 member states of the Bureau International des Expositions, holding splashy lobbying events in the French capital.

South Korea's southeast city of Busan is competing against Saudi Arabia's Riyadh and Italy's Rome.

Rome has placed a heavy emphasis on human rights and democracy in its bid to host the Expo, painting itself as a more ethical option than Riyadh, which is widely seen as the frontrunner.

"Rome is the most credible city for an expo which has as an objective sustainable development, an expo which respects human rights, diversity, dialogue, inclusion, women, the LGBTQ+community, unions," City Mayor Roberto Gualtieri told a conference last week.

"Certainly we have less economic capital to spend than others have done in asking for a direct vote … (but) if money that comes from the sale of fossil fuels is worth more than anything else, then we tell the world, 'watch out how these events will turn out'," he added.

HORSE-TRADING

A win for Saudi Arabia would be the icing on the cake for de-facto ruler Crown Prince Mohammed bin Salman's ambitious Vision 2030 programme, which aims to wean the country off its oil dependency.

Critics say Prince Mohammed is using the event to improve his country's image after the 2018 murder of prominent Saudi journalist Jamal Khashoggi, which Western leaders believe was ordered by the crown prince.

Riyadh won French support for the first round of voting, with Macron advisers saying it was in return for some Saudi help on other issues at the heart of French diplomatic priorities.

A European official said it had to do with Lebanon, without specifying. But the Macron adviser has said the commitment is limited to the first round of voting. More than one vote will be necessary if no country gets a majority at the first ballot.

Meanwhile, campaigning has been in full swing in Paris.

South Korean President Yoon Suk Yeol made a final push during a trip to Paris, saying the Expo would be a chance for South Korea to give back to the world after benefiting from international aid in the aftermath of the 1950-53 Korean War.

Italian Prime Minister Giorgia Meloni personally got involved in trying to persuade international leaders to back the Rome bid, giving it her full political backing.

However, she is not scheduled to travel to Paris on Tuesday – a sign for some that she believes it is likely to be a lost cause.

Rome is looking to use the Expo as a way of attracting investment, much as Milan did when it successfully hosted the 2015 Expo.

That was the last Expo to be staged in Europe and Rome says it is only fair the continent get it back in 2030, given Dubai staged it in 2020 and Osaka, Japan will in 2025.