Israeli architects will resign from their international union if a boycott policy is pursued, a leading figure has revealed.

Yitzhak Lipovetsky-Lir, former president of the Israeli Association of United Architects (IAUA), issued the warning as he arrived in London to meet British architect union leaders yesterday.

In his first major interview with foreign media since the Royal Institute of British Architects (Riba) voted in March to urge the International Union of Architects (IUA) to suspend Israeli members, Mr Lipovetsky-Lir said he was “working on a peace mission”.

But he warned that if IUA members backed Riba at world architecture’s annual conference in South Africa in August, then Israelis “will leave the organisation”.

Mr Lipovetsky-Lir said he had received assurances from IUA president Albert Dubler that the global body would not support Riba’s proposals in Durban.

“He told me they would reject the Riba motion. He did not say why and we have not had a written decision from them. It has given us some confidence. I trust him,” he said.

In London, Mr Lipovetsky-Lir will see Riba president Stephen Hodder in a meeting set up with the help of British architects.

He said: “We thought Riba might change its decision. We will try to convince them. I’m coming on a mission of peace. I don’t want to close them down, I don’t want an apology — I just want to be better acquainted. We want to invite Riba to Israel to see what’s going on.”

The Israeli architect has been leading his country’s response to the controversy and said there was “shock and surprise” following the British group’s initiative.

“I wrote to David Cameron. He had just promised the Knesset that he would deal with boycotts. But he did not respond to me.”

Mr Lipovetsky-Lir criticised Riba for singling out Israel. “I just want to explain to them that this is not the issue to raise in the IUA because it will create a real danger for the future,” he said.

The UK Lawyers for Israel group has written to the IUA at the request of Israeli architects to warn of the legal consequences of backing a boycott of Israel.

UKLFI chair Jonathan Turner said: “Our understanding is that the IUA will reject Riba’s proposals.”

Lifschutz Davidson Sandilands, the firm which designed the JW3 Jewish community centre in London, last week collected a Riba award for its work on the building.