In an awkward moment the Labour grandee, who is campaigning for Britain to remain in the EU, was shown the faces of EU officials including Donald Tusk, the president of the European Council, and Mario Draghi, the president of the European Central Bank.

Yet despite being a supporter of Remain, Ms Harman simply asked: "Who are they?"

BBC Sunday Politics presenter Andrew Neil said: "These are the people that you think should be running us. You don’t know who they are."

"Doesn’t that tell you everything you need to know about the EU," quipped Isabel Oakeshott, a political journalist who helped write a controversial biography of David Cameron.

Ms Harman, speaking during a discussion about gender equality in the EU campaign, said: "I don’t know who they are. I can’t answer for them.

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