British Labour candidate Keir Starmer, 57, has promised to work to end anti-Semitism within his party, if he is elected its leader.
Speaking on BBC One, Starmer said his party "should have done more on anti-Semitism."
"If you are anti-Semitic you shouldn’t be in the Labour party. What I would do is lead from the top and say it's my responsibility to deal with it. I wouldn’t say it's for somebody else. I want the files, I want to know the numbers on my desk so that I can monitor this."
Starmer also said he argued for automatic expulsion. "It seemed to me that if you have been chucked out of the Labour party for supporting another political party, you should be chucked out for being anti-Semitic," he explained.
The party is expected to replace its current leader, Jeremy Corbyn, on April 4, 2020.
Corbyn has faced ongoing accusations of anti-Semitism, both over his history of hostility towards Israel and support for anti-Israel terrorist groups, as well as the rise in anti-Jewish rhetoric within the party.