Gordon Brown will today increase the pressure on Iran to give up its nuclear programme by condemning as “totally abhorrent” Mahmoud Ahmadinejad’s threats against Israel.

Tehran faces a series of sanctions against its oil and gas industries unless it halts attempts to develop its atomic capability within two weeks, senior British diplomats said last night.

Mr Brown is to use a speech to the Knesset in Jerusalem - the first by a British Prime Minister - to make his strongest attack so far on the Iranian regime while pledging an “unbreakable partnership” with Tel Aviv.

“To those who question Israel’s very right to exist and threaten the lives of its citizens through terror, we say: the people of Israel have a right to live here, to live freely and to live in security,” he will say. “And to those who believe that threatening statements fall upon indifferent ears, we say in one voice: that it is totally abhorrent for the President of Iran to call for Israel to be wiped from the map of the world.”

Mr Brown will say that Tehran must end its nuclear ambitions or face concerted international action. “Iran now has a clear choice to make: suspend its nuclear programme and accept our offer of negotiations or face growing isolation and the collective response not of one nation but of many nations.”

Sanctions aimed at disrupting Iranian oil refineries and gas facilities are being prepared in case Iran fails to respond satisfactorily to demands that it suspends uranium enrichment within two weeks, senior British sources said.

The Prime Minister’s remarks are part of a coordinated effort to increase pressure to accept a “freeze for freeze” offer, under which further international action is suspended in return for a moratorium on enrichment. Javier Solana, the European Union’s special envoy, said that Iran had made insufficient progress during talks with Saeed Jalili, its chief nuclear negotiator, over the weekend. The US, which sent a representative to the talks for the first time, said that Iran faced the prospect of confrontation unless it accepted the offer.

Mr Brown’s speech to the Knesset comes at the end of his first visit to Israel as Prime Minister, during which he also sought to add impetus to restarted peace talks with the Palestinians. Speaking with President Abbas in Bethlehem, Mr Brown pledged a £30 million package of economic and security help for the Palestinian National Authority. He said that the security wall erected by Israel was “graphic evidence of the urgent need for justice for the Palestinian people” and called on Tel Aviv to stop the spread of settlements. “We want to see a freeze on settlements. Settlement expansion has made peace harder to achieve,” the Prime Minister said. “It erodes trust, it heightens Palestinian suffering, it makes the compromises Israel will need to make for peace more difficult.” His appeal came as a human rights group released a video of an Israeli soldier shooting a rubber bullet at a Palestinian man who had been arrested and bound during a protest against the wall Israel has built inside the West Bank to stop attacks on its territory.

Mr Brown will tell the Knesset that he is a “true friend” of Israel, emphasising his attachment to the country and pointing out that his father, a Presbyterian minister, had a “deep and lifelong affection” for Israel. “There was never a time as I was growing up that I did not hear about, read about or was not surrounded by stories of the struggles, sacrifices, tribulation and triumphs as the Israeli people built their new state,” he will say.

Yesterday Mr Brown laid a wreath at Yad Vashem, the Holocaust memorial in Jerusalem. In the guest book he wrote: “Nothing prepares you for the story that is told of the atrocities that should never have happened and the truth that everyone who loves humanity should know. We must always remember so that prejudice, discrimination, racism and antiSemitism [can] be banished from our world.”

Later he visited the Church of the Nativity in Bethlehem.

Tomorrow he will make a statement to the Commons on expected troop withdrawals from Iraq, in which almost all soldiers could leave the country within a year.

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