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.

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.

He stated, 'We argued, and we listened to the arguments of the others, and after that we made a secret vote... The result 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'.

Other countries who could join the boycott include Iceland, which has yet to confirm its participation until a meeting of its board next week.

Eurovision author Dean Vuletic suggested that upcoming weeks will be tense as countries confirm whether or not they're going to participate in Eurovision next year. The loss of financial contributors could severely impact the event's future.

This crisis highlights the divisions within the music community and raises questions about the essence of Eurovision's motto: 'United by music.'