Liberal Democrat MEPs have made Diana Wallis their leader for the second time after her predecessor quit in a row over emails to a Jewish constituent.
Diana Wallis replaces Chris Davies, who quit last month
Chris Davies resigned after telling a woman who justified Israel's policy towards Palestine that he hoped she enjoyed "wallowing in her own filth".
Ms Wallis, who is MEP for Yorkshire and the Humber, previous served as leader between 2001 and 2004.
She beat fellow MEPs Andrew Duff and Saj Karim in the leadership vote.
She said: "Now that David Cameron wants to marginalise the Conservatives in the European Parliament and Tony Blair no longer makes any mention of Europe at all, the Liberal Democrats in Brussels are well placed to frame the argument on the future of Europe."