Joan Ryan, the LFI chair, read a message from Mr Corbyn, but was disrupted by hecklers who shouted “where is he, why’s he not here?”.
Ms Thornberry said Mr Corbyn could not be at the reception because he was spending time preparing for his “big speech” to the conference on Wednesday. As she spoke, Mr Corbyn was at a party being held by the Mirror newspaper. He later tweeted pictures of himself at three receptions run by trade unions.
She went on to say it was “disgraceful” that the Conservative Party’s manifesto ahead of June’s general election had not referred at all to Israel and the Palestinians. It was, she said, “humiliating” for the government.
“Our foreign policy is being held in abeyance, we are just holding our breath waiting for Donald Trump to tell us what British foreign policy will be, and I think it’s disgraceful,” she added.
“We have a role to play in the Middle East and we should be a little less arrogant but a bit more proud. We have a role to facilitate talks.”
A Labour government would immediately recognise a Palestinian state, Ms Thornberry said, repeating a manifesto pledge, and adding that it was the “appropriate time” given the centenary of the Balfour Declaration later this year.
The Shadow Foreign Secretary said she sent condolences on behalf of the whole Labour Party to the families of the Israelis killed in a terror attack near Jerusalem.
Stav Shaffir, the Labour Knesset member, led the reception attendees in a moment’s silence for those who were murdered.
Mark Regev, Israel’s ambassador to Britain, praised Labour’s role in the Balfour Declaration and said the party had a “proud history of supporting Zionism”.
Referring to the calls for Jewish Labour groups to be expelled from the party, Mr Regev asked whether the same would apply “to some of Labour’s greatest luminaries – Harold Wilson, Manny Shinwell, Michael Foot” who had also supported Israel.
The attacks from some of those on the hard-left of the party were, he said, “clearly just anti-Jewish bigotry, plain and simple”.
The warmest welcome at the event was reserved for Iain McNicol, Labour’s general secretary, who appeared on stage alongside the speakers.
