The co-director of a leading left-wing Israeli peace group has claimed a two-state solution to the conflict with the Palestinians cannot now be achieved.

Itay Epshtain, co-director of the Israeli Committee Against House Demolitions (ICAHD), said: “Because of the way Israel has acted, we are realising that the window of opportunity for a two-state solution has closed. Where we go next, no one knows.”

His comments echo those of Liberal Democrat deputy leader Simon Hughes last month, whose suggestion that the international community should consider a one-state solution was criticised by Israel’s ambassador to Britain, Daniel Taub.

Mr Epshtain said: “The observation made by Simon Hughes is one that is shared by many, including the UK’s mission to East Jerusalem.

“There are a few solutions — there could be a regional confederacy, or a one-state solution with equal rights for everyone. Regardless of the exact formulation, we need to set the principles — respect for all, and protection and fulfilment for Palestinians’ right to self-determination. That could take many shapes. The likelihood of two separate, sovereign states is very low.”

Mr Epshtain will speak at an Amnesty International event — Discrimination, Displacement and Despair: The impact of Israel’s prolonged occupation — in London on Tuesday.

Amnesty has repeatedly defended its work with Israelis and Palestinians from criticism aimed at it by pro-Israel groups based in Britain.

But Mr Epshtain, a former executive director of Amnesty’s Israel branch, said: “Amnesty International’s work has been more than just fair and balanced. The reason its work here [in Israel and the Palestinian territories] is considered to be so solid is because it’s ingrained in international law.

“At ICAHD we model ourselves around the same sort of work so that what we say is not politically inflammatory, and substantiated by facts on the ground.”