Theresa May has said that greater efforts must be made to combat anti-Semitism and “without its Jews, Britain would not be Britain”.

The Home Secretary asserted that the country would not be the same without people of different faiths, while she was speaking at an event in London to commemorate the victims of the Paris attacks.

Mrs May praised the contribution Jewish people make to the UK and said that the unity displayed in the French capital and around the world, with people repeating “Je suis Charlie” was “tremendous”.

But she said she was troubled at the threats now faced by Jewish people. "I never thought I would see the day when members of the Jewish community in the United Kingdom would say they were fearful of remaining here in the United Kingdom."

In pictures: Extremists in the EU Show all 6 1 /6 In pictures: Extremists in the EU In pictures: Extremists in the EU France: Marine le Pen Marine Le Pen, 45, took over the Front National (FN), the party that her father founded, in 2011. He himself described her as “a big, healthy, blonde girl, an ideal physical specimen." She claims to have cleaned up the FN and succeeded in pushing her anti-European, anti-euro and anti-immigration agenda into the EU political mainstream AFP In pictures: Extremists in the EU Germany: Udo Voigt He will be the first German neo-Nazi to enter the European Parliament. The former army officer, born in 1952, was jailed in 1995 for inciting racial hatred. Formerly the leader of the far right National Democratic Party (NPD), Voigt was convicted in 2009 after he was caught handing out flyers at the World Cup which argued that a black player was not entitled to play for Germany, whose national team – the literature argued – should be made up only of white players. AFP In pictures: Extremists in the EU Denmark: Morten Messerschmidt Leader of the Danish People’s Party, which won 27 per cent of the vote. His party has rammed 20 laws relating to immigrants and asylum-seekers through the Danish parliament, giving it the most anti-foreigner legislation in Europe. His party calls Islam “a fascist ideology” and rails against “East European criminal gangs”. One party strategist said “blood ties” to Denmark should be required for citizenship, though the statement was quickly retracted. EPA In pictures: Extremists in the EU Hungary: Krisztina Morvai A senior member of Jobbik, the anti-Semitic and anti-Roma party on Hungary’s far right wing. In 2009, she attracted international publicity after declaring: “So-called proud Hungarian Jews should go back to playing with their little circumcised dicks.” In 2009, she cancelled an interview with a British newspaper, declaring in tones of outrage: “I am a decent politician and the mother of three children, yet you in the west keep portraying me as a Nazi and a Fascist.” AP In pictures: Extremists in the EU Italy: Mario Borghezio MEP for Italy’s notoriously racist Northern League, he has relentlessly attacked the nation’s first black cabinet minister, Cecile Kyenge, minister for integration, claiming she would import ‘tribal traditions’ into the Italian government. Other elected members in the party called her “an orang-utan” and suggested that someone should rape her, so she would understand how the victims of Somali rapists felt. He attracted attention by lobbying for the creation of an EU archive of UFO sightings. Getty In pictures: Extremists in the EU Greece: Eleftherios Synadinos Fabulously mustachioed retired lieutenant-general in the Greek army, he was one of Golden Dawn’s top candidates in the European elections, at which the overtly neo-Nazi party obtained more than 9 per cent of the vote. With its black-shirted assault squads, the Hitler photos and the party’s swastika-inspired logo, it has been accused of being a criminal organisation. Its website declares: “We aren’t the quiet birds of peace time, we are birds of the storm and the hurricane.”

Commenting on the French prime minister Manuel Valls' statement: “If 100,000 Jews leave, France will no longer be French, the French Republic will be judged a failure," Mrs May said: “It is a sentiment I well understand, one that holds true for Britain.

“Without its Jews, Britain would not be Britain, just as without its Muslims, Britain would not be Britain - without its Sikhs, Hindus, Christians and people of other faiths, Britain would not be Britain,” she added.