US presidential candidate Beto O’Rourke has called Benjamin Netanyahu “racist” and an obstacle to peace in the wake of the Israeli Prime Minister’s election pledge to annex Jewish West Bank settlements.

Speaking at a campaign stop at the University of Iowa, Mr O’Rourke said: “The US-Israel relationship is one of the most important relationships that we have on the planet.

“And that relationship, if it is to be successful, must transcend partisanship in the United States, and it must be able to transcend a Prime Minister who is racist… who wants to defy any prospect for peace, who threatens to annex the West Bank, and who has sided with a far-right, racist party in order to maintain his hold on power.

“I don’t think that Benjamin Netanyahu represents the true will of the Israeli people, or the best interest of the US-Israel relationship, or any path to peace for the people of the Palestinian Authority, the Gaza Strip and the State of Israel.”

Mr O’Rourke, who narrowly lost to incumbent Ted Cruz in the 2018 US Senate race in Texas, last month announced his bid for the Democratic Party nomination for president in 2020.

According to early national polls, he is forecast to win between five and 12 per cent of the vote in Democratic primaries, trailing his more established rivals, including Joe Biden and Bernie Sanders.

Beto O'Rourke: "The US-Israel relationship is one of the most important relationships that we have on the planet. And that relationship, if it is to be successful, must transcend partisanship in the United States, and it must be able to transcend a Prime Minister who is racist." pic.twitter.com/cZoEerEU82

— The Hill (@thehill) April 7, 2019

Mr Netanyahu provoked consternation on Saturday with a last-minute election pledge to officially annex all land in the West Bank occupied by Israel.

It was interpreted as a pitch to ultra-nationalist voters, whose votes he is competing for in a crowded field of right-wing parties.

If implemented, the annexation of Jewish-occupied land in Palestinian territories would represent a major blow to the peace process, since it would make a Palestinian state in the West Bank unviable.

The West Bank is home to an estimated 400,000 Jewish settlers, who began occupying the territory after it was captured in the Six Day War of 1967.

Another 200,000 Jews live in East Jerusalem, while 2.5 million Palestinians live in the West Bank.

Settlements are considered illegal under international law, although this is disputed by Israel.

Hannah Weisfeld, the director of UK-based pro-peace movement Yachad, said Mr Netanyahu’s announcement “shows the extent to which he is willing to completely undermine the possibility of any kind of resolution to the Israel-Palestine conflict”.

She added: “His words should serve as alarm bells to supporters of Israel who understand that Israel cannot survive as a Jewish and democratic state, without the conflict being resolved.

“The question we should be asking of Netanyahu and others who support this plan is: Who are the real Zionists in these elections? Those who will do anything to stay in power, or those that have Israel’s real, long-term safety and security at heart?”

Voters will go to the polls in the Israeli legislative election on Tuesday.