Jeremy Corbyn will meet Jewish leaders for talks after weeks of turmoil over his handling of anti-Semitism in the Labour party.
The 5pm showdown comes after protests, criticism from Labour MPs and international condemnation over the way the Opposition leader has dealt with hostility to Jews.
Organisations representing Jewish communities will call on Mr Corbyn to use his “personal authority” to drive through changes to wipe out the problem in the party.
The Board of Deputies of British Jews and the Jewish Leadership Council (JLC) said there must be “action not words” when they accepted his invitation to meet.
Labour Jewish MPs spoke out about anti-Semitism in the party during a debate in Parliament and warned “enough is enough”.
London Mayor Sadiq Khan admitted Jewish people who would like to vote Labour are “finding it very difficult” because of the party’s handling of the issue.
Prime Minister Theresa May accused Mr Corbyn of allowing anti-Semitism to “run rife” in his party.
The Board of Deputies, made up of almost 300 deputies directly elected by synagogues and community organisations, and the JLC, a charity supporting the Jewish community, took the unusual step of protesting outside Parliament in March before delivering an open letter to a meeting of Labour MPs and peers about their concerns.
The Labour leader has said he is “happy to meet” the two bodies “without any preconditions” and pledged to hear their concerns about tackling anti-Semitism in the Labour Party.
In a letter accepting his invitation, the organisations thanked Mr Corbyn for his commitment to addressing the “anguish” caused by anti-Semitic incidents.
But they said recent events had not been “reassuring” for Jewish people in Britain, and told him he must root anti-Semitism out of his party.
And they later refused to attend a roundtable meeting Labour had proposed to hold on Wednesday with a wider group of Jewish organisations that reportedly included Jewish Voice for Labour, a recently established group that has downplayed the issue.
Supporters of Mr Corbyn have claimed the row has been stoked up by his opponents to damage him.
The Labour leader has admitted the party needs to “do better” in the fight against abuse and has issued an apology for the “pain and hurt” caused by anti-Semitism.
Israel’s Labor party suspended relations with Mr Corbyn over the “hostility” it claims the leader has shown to the Jewish community.