Israel is in the midst of a third intifada and close to losing the last opportunity it has to prevent future uprisings.

This was the warning sounded by Danny Seidemann, a lawyer and expert on Jerusalem's borders, during a Security Conference organised by left-leaning Zionist NGOs Yachad and the New Israel Fund in London on Sunday.

Mr Seidemann said: "I have been out on the streets of Jerusalem for the past 25 years. Now I can only go when accompanied by a Palestinian friend - that was never the case before."

He said that during the entire Second Intifada, from 2000-2008, Israel arrested 270 Palestinians in East Jerusalem for security-related offences. Between September 13 and October 31 2015, Israel arrested 797.

"Since the outbreak of violence in 2014, Israel has arrested close to 1.5 per cent of all Palestinian boys in East Jerusalem. That is a staggering number. We are in the midst of a popular uprising the likes of which we have not seen since 1967."

Echoing recent calls by IDF and Israeli intelligence chiefs for Israel to create more economic opportunities for young Palestinians, Mr Seidemann added: "We can fend off every external threat you want - Daesh, Hizbollah, Al Qaeda - but we have no operational answer to occupation."

In addition, he said: "We are very close to losing the possibility of ending that occupation. There is only one way to end the occupation: with a border. And we know where that border goes. But that border is being jeopardised by a government that is wilfully creating a one-state reality."

Although not all speakers agreed that a two-state solution was the only answer - both Palestinian cultural commentator Aziz Abu Sarah and Israeli journalist Anat Saragusti argued that they would accept a wide variety of peace agreements - there was a consensus that Israel's occupation of the West Bank was the biggest obstacle to its security in the longer term.

Haaretz journalist Barak Ravid, however, put it to the conference that there was no chance of any peace deal in the next "10-20 years", and to think any other way was to fail to acknowledge reality.

"In Israel there is the most right-wing government you have in our history, that is opposed to the two-state solution. This government is totally controlled by the settler lobby, from within and without. There is no scenario in which this government is going to do anything about the two-state solution."

Meanwhile, he said, the Palestinian Authority was a near-dictatorship, and Fatah and Hamas are nowhere near overcoming their differences.

"The situation on the ground is a third intifada. This is not about finding the right ideas or formula. It's futile."