The government is to adopt an official definition of antisemitism in order to help crack down on hate crime.

Theresa May, the Prime Minister, will announce later today that there will be “one definition of antisemitism”.

Downing Street believes an agreed interpretation will enable action to be taken more effectively against perpetrators, whereas some currently evade it because of differences over what constitutes antisemitism.

It proposes to use the working definition agreed earlier this year by the International Holocaust Remembrance Alliance.

According to the IHRA, “antisemitism is a certain perception of Jews, which may be expressed as hatred toward Jews. Rhetorical and physical manifestations of antisemitism are directed toward Jewish or non-Jewish individuals and/or their property, toward Jewish community institutions and religious facilities.”

Mrs May is expected to say it is “unacceptable that there is antisemitism in this country. It is even worse that incidents are reportedly on the rise."

Sir Eric Pickles, the government’s envoy for post-Holocaust issues, told the BBC the new definition "catches up with modern antisemitism".

It was, he said, “important not to conflate Jewish people with Israel... and that actually is the point in the definition."

Examples of antisemitism given by the IHRA include justifying harming Jews in the name of radical ideology or making demonising or stereotypical allegations about Jews such as controlling the media or the economy.

Other examples of antisemitism may include denying the Jewish people their right to self-determination such as claiming the state of Israel is a “racist endeavour”, comparing Israeli policy to the Nazis, accusing Jews of  being more loyal to Israel than their own countries or claiming Jews have exaggerated the Holocaust.

The Labour Party has backed the move.

Chief Rabbi Ephraim Mirvis said: "I would like to salute the Prime Minister for her leadership on this issue and for the government's commitment to tackling the scourge of antisemitism in our society.

"For some, calling out antisemitism has long felt like trying to strike a moving target with competing views about what is and is not acceptable. My hope is that the adoption of this definition will provide a clarity which will herald a far more effective discourse on the ways that we can highlight and challenge antisemitism wherever it is found.

"I would also like to welcome the Labour Party's support for the definition and call upon other political parties and organisations worldwide to do likewise."

Jonathan Arkush, Board of Deputies president said: "With antisemitism on the rise it has become essential to have a clear definition against which to assess attitudes that are or may be racist.  The adoption of the IHRA formulation will bring clarity and consistency and I warmly welcome its adoption by the government."

Simon Johnson, Jewish Leadership Council chief executive, said: “The recommendation of a definition of antisemitism was made by the Home Affairs Select Committee in their recent report, and it is welcome that the government is to accept this recommendation and institute a definition of antisemitism.

"I would urge the government to work closely with communal bodies such as the CST in formulating the definition, and to then ensure it is widely adopted within civil society”.

The Community Security Trust said it was "an important step" that would help reduce antisemitism in Britain.

John Mann MP, chair of the All Party Parliamentary Group Against Anitsemitism, said: “Our All-Party Group called for adoption of this definition 10 years ago.

"The Inter-Parliamentary Coalition for Combating Antisemitism (ICCA) of which I am chair, gave backing for this move at the IHRA conference in Berlin this May. The IHRA is considered to be one of the most respected international bodies.

"The UK police force has adopted it, the Germans have adopted it and as such, here in the UK we should too. This is a big moment and the culmination of 10 years of campaigning on this issue. I have written to congratulate the Prime Minister on this move. We will be backing this if presented to Parliament.”

Karen Pollock, chief executive of the Holocaust Educational Trust, said: “This definition will leave people in no doubt when a line has been crossed – a crucial step in the fight against antisemitism.

"As representatives for the UK to the International Holocaust Remembrance Alliance we are delighted this has been welcomed and adopted by Theresa May’s government.”

Rabbi Danny Rich, senior rabbi of Liberal Judaism, said: "Today’s attempt by the British government, with cross-party support, to clarify a working definition of antisemitism is a welcome one.

"However, definitions of antisemitism have existed before and failed to assist those who have suffered from it, while some of the perpetrators have still evaded sanction.

"Context, in such cases, is frequently everything, and in a modern democratic liberal society – which Britain is – the balance between freedom of speech and sanction against those who seek to use it to harm others needs to be maintained."

Dr Moshe Kantor, European Jewish Congress president, said: "For many years the EJC has been lobbying for the adoption of a standard definition of antisemitism and we are delighted that this is bearing fruit with the UK leading the way.

"Up until now we have the absurd situation whereby antisemitism is defined by the perpetrators not by the victims, which makes it unique amongst all definitions of racism and xenophobia. Now, the perpetrators of antisemitism will be given clear red lines that they are not to cross and this is a very important development.

"We applaud and welcome this decision and call on other European states to follow suit."

The Council of Christians and Jews said in a statement: "At a time of deep uncertainty for many people, 'hatred of Jews' is averse to strong community and positive cohesion between faiths. This authorised definition is a significant step in combating the deeply worrying rise in antisemitic hate crime reported for the first six months of this year.

"We hope that the new definition will enable the authorities to identify and deal with antisemitic incidents when they arise and educate to ensure that they are eradicated in the future."