Two months ago, Theresa May told the Board of Deputies dinner that the government would “not tolerate antisemitism in any form”.

Now is the time for her to prove it.

This weekend, Gábor Vona, the leader of the neo-Nazi Hungarian Jobbik party, is due to address a meeting in central London. Even if the meeting is allowed to go ahead, Mr Vona should not be allowed to address it — because he should not be allowed to enter the country.

His visit has no other purpose than stirring up hatred — hatred which has no place in Britain. Of all the far-right parties that have sprung up in the wake of the European recession, Jobbik is by far the most successful, holding 12 per cent of parliamentary seats.

For Hungarian Jews — and other minorities — that is a frightening prospect. They face a daily threat from neo-Nazis, who are gaining in support.

We are privileged to live in a country where the far right repeatedly fails to make any real impact. The Home Secretary should make clear to Jobbik that its leaders will never be allowed to preach their poison here.