Thursday marked the biggest crisis in the history of the Eurovision Song Contest.

Four countries pulled out over Israel's continued participation in the competition, and more may follow.

The boycott includes Ireland, which has won seven times - a tally matched only by Sweden - and five-time winner the Netherlands.

Spain, one of the contest's biggest financial backers, and Slovenia, are also out.

The row exposes a deep rift within the Eurovision family. And it's a situation that's been looming for years, amid festering tension over Israel's conduct during the war in Gaza.

There has also been consternation over the voting and campaigning processes after Israel came top of the public vote this year - finishing second overall after the jury votes were taken into account.

Israel, meanwhile, called the decision to keep it in the contest a victory over critics who had tried to silence it and spread hatred.

'We argued, and we listened'

Thursday's summit with the European Broadcasting Union (EBU) brought the divisions within the Eurovision family to the fore.

There was no direct vote on Israel's place in Eurovision, but the country's future participation was effectively tied to a ballot among broadcasters about proposed new rules for campaigning and public voting.

Sixty-five per cent of members of the EBU voted in favour of that change. Ten per cent abstained.

Roland Weissmann, director general of ORF, the public broadcaster in Austria, next year's host country, said there were heated discussions, but that it was a fair process.

We argued, and we listened to the arguments of the others, and after that we made a secret vote, he told the BBC World Service. That's democracy, and the majority voted for new, stronger rules by the song contest.

The result also meant Israel was cleared to compete - but sparked others to withdraw.

According to Spain, the crisis was avoidable. This point should never have been reached, said the president of broadcaster RTVE in an angry social media post ahead of Thursday's summit.

Jose Pablo Lopez said he had lost faith in Eurovision's organisers, saying they had been swayed by political and commercial interests.

He added that organisers should have addressed Israel's alleged manipulation of the public vote should have resulted in sanctions at an executive level, instead of asking EBU members to decide on any consequences.

Israel denies attempting to influence voting at the contest, and says its publicity campaigns were acceptable within Eurovision rules.

More countries to boycott?

Other countries who could join the boycott include Iceland, which said it would not confirm its participation until a meeting of its board next week.

On Friday, Belgium and Sweden, which had been among those also considering their positions, confirmed they would stay in the contest.

Finland said its attendance was conditional on Eurovision securing a large number of other participants, adding: The costs for participating organisations must not increase unreasonably.

Eurovision author and academic Dean Vuletic told BBC Radio 4's Today programme on Friday: The next couple of weeks are going to be tense as countries confirm whether or not they're going to participate in Eurovision next year.

But I think we will see more boycotts.

The deadline for countries to confirm their participation is Wednesday, 10 December.

Free speech factor

Amit all the drama, there's a small detail in the EBU's press release that sheds some light on why many countries were keen to keep Israel's broadcaster, Kan, in the contest.

During a wide-ranging discussion, it says, fellow broadcasters took the opportunity to stress the importance of protecting the independence of public service media and the freedom of the press to report, not least in conflict zones such as Gaza.

That's because Kan is independent of Israel's government, and has often found itself at odds with prime minister Benjamin Netanyahu's administration.

Public broadcasters take part, not countries, ORF's Mr Weissmann said. It's not the government of Israel, it's the public broadcaster.

Kan's association with Eurovision is believed to have protected it from threats of closure or cuts - because the government recognises the positive PR power of taking part in the contest.

Severely wounded

That all means the competition is severely wounded, but the injuries aren't fatal... yet.

Thursday was a very seismic day in Eurovision history, according to Callum Rowe from The Euro Trip podcast.

Fans are equally up in arms and devastated at what happened, he told BBC Radio 5 Live.

We're losing countries that have got an illustrious and storied history in the competition.

Eurovision director Martin Green estimates that 35 nations will still take part next year in Vienna. The loss of four competitors is balanced by the return of three others – Moldova, Romania and Bulgaria – who have skipped the last couple of years.

The row will cast a long shadow of the contest next year, and probably in future years, too. With much of the music industry throwing its weight behind Palestinian causes, it may prove harder than normal to find artists willing to share the stage with Israel.

But Mr Weissmann insisted he didn't think the boycott would be damaging for Eurovision as it approaches its 70th anniversary in 2026. It was built 10 years after World War Two - united by music - and that's what it is all about.