Theresa May today warned Jeremy Corbyn that 'anti-Semitism is racism' as she demanded he finally act to stamp out vile abuse in Labour.

The Prime Minister offered her backing to ex-chief rabbi Jonathan Sacks who yesterday branded Mr Corbyn an 'anti-Semite' and compared him to Enoch Powell.

Speaking in Nigeria during her tour of Africa, Mrs May said Lord Sacks raised 'significant concerns' and was only the latest to speak out.

She said: 'I think the leader of the Labour Party needs to respond to those concerns.'

In other developments today, the British Board of Deputies today wrote to Labour's General Secretary Jennie Formby with a renewed demand for action against anti-Semitism.

Chief Executive Gillian Merron said it was 'beyond contention' Mr Corbyn had shared platforms with anti-Semites and terrorist sympathisers.

And she said a video revealed by MailOnline of Mr Corbyn speaking in 2013 showed the Labour leader using a 'classic racist trope'.

A petition launched by the Campaign Against Anti-Semitism for Mr Corbyn to resign has been signed by more than 30,000 people as the furious row continues to escalate.

Mr Corbyn is facing a fresh storm of controversy after MailOnline unearthed another video showing him accusing MPs of having their contributions to a debate written by the Israeli ambassador.

Theresa May (pictured today in Nigeria) warned Jeremy Corbyn that 'anti-Semitism is racism' as she demanded he finally act to stamp out vile abuse in Labour

The former chief rabbi Jonathan Sacks today lashed Jeremy Corbyn (pictured in Edinburgh last week) as an 'anti-Semite' who 'defiles our politics'

Lord Sacks (file image) said a tape of him attacking English Zionist Jews was the most offensive remark by a British politician since Enoch Powell's Rivers of Blood speech in 1968

The Campaign Against Anti-Semitism launched its petition three days ago amid growing anger at Mr Corbyn's response to anti-Semitism in his party. It has been signed by 27,072 people so far (pictured)

Rows over anti-Semitism have rocked Labour all summer after the party refused to adopt in full an internationally accepted definition of hatred against Jews.

The party is expected to finally do so next week - but has been claimed could still add caveats to its rulebook to protect members who accuse the Israeli government of racist treatment of Palestinians.

Ms Merron said: 'While Labour could have used the summer to focus on any number of other serious challenges facing this country, the leadership has chosen to make its priority a fight with British Jews about antisemitism.'

Labour frontbencher used £40,000 of taxpayers' cash to pay off his Jewish ex-lover assistant MP Khalid Mahmood pictured with his former lover Elaina Cohen A Labour MP paid off his Jewish Parliamentary assistant with taxpayers' money after she accused him of religious discrimination, it was claimed last night. Khalid Mahmood, the shadow foreign minister for Europe and MP for Birmingham Perry Barr, was taken to an employment tribunal by his former lover and assistant Elaina Cohen, the Daily Telegraph reported. Mr Mahmood's £40,000-worth of legal and staffing costs during the case, which was settled out of court with a non-disclosure agreement, were paid for by the parliamentary expenses system. The MP, 57, was criticised for claiming nine nights at a luxury hotel in Kensington costing £1,350 in 2009, during his relationship with Miss Cohen. The expenses watchdog Ipsa, the Independent Parliamentary Standards Authority, has now come under fire as it is revealed the transparent expenses system can be used to fund secret gagging orders. Official records show Mr Mahmood claimed £900 expenses for 'lawyers' fees', and £1,500 in 'legal costs'. During the tribunal he was also granted nearly £37,000 from Ipsa to pay staff covering for Miss Cohen. Claims of religious discrimination first surfaced when Mr Mahmood disciplined Miss Cohen after she called another Labour MP, Naz Shah, an 'anti-Zionist' in a tweet in 2016. Mr Mahmood suspended his former lover and began an internal disciplinary process against her. Meanwhile, Naz Shah was suspended for anti-Semitic Facebook posts. When Miss Cohen returned to work she realised she did not have a job. Her religious discrimination claim was settled out of court in 2017. Miss Cohen still works for Mr Mahmood. Advertisement

'It is now beyond contention that he has repeatedly shared platforms and joined events with antisemites, terrorist-sympathisers and other extremists, not to challenge them, but to show solidarity.

'In 2013, Mr Corbyn also made comments about 'Zionists', which appear to imply that they are somehow 'un-British'. This is a classic racist trope.'

'We reject the idea that the above is excusable on the basis that it represents 'peace-making'.

'Peace-makers speak to different parties to a conflict and seek to show empathy with both and find common ground. There is no evidence that Mr Corbyn has sought to engage with challenging – or even mainstream – Israeli voices.

'Through these actions, he has not advanced the cause of peace and, potentially, even set it back.'

Lord Sacks told the New Statesman: 'The recently disclosed remarks by Jeremy Corbyn are the most offensive statement made by a senior British politician since Enoch Powell's 1968 'Rivers of Blood' speech.

'It was divisive, hateful and like Powell's speech it undermines the existence of an entire group of British citizens by depicting them as essentially alien.'

Lord Sacks said Mr Corbyn could only be judged by 'his words and his actions'.

In the remarks revealed by MailOnline, which have been widely condemned as anti-Semitic, Mr Corbyn said: 'They clearly have two problems.

Continuing his attack on the Labour leader as 'low, dishonest and dangerous', Lord Sacks said: 'He has given support to racists, terrorists and dealers of hate who want to kill Jews and remove Israel from the map.

'When he implies that, however long they have lived here, Jews are not fully British, he is using the language of classic pre-war European anti-Semitism.

'When challenged with such facts, the evidence for which is before our eyes, first he denies, then he equivocates, then he obfuscates.

'This is low, dishonest and dangerous. He has legitimised the public expression of hate, and where he leads, others will follow.'

He added: 'Now, within living memory of the Holocaust, and while Jews are being murdered elsewhere in Europe for being Jews, we have an anti-Semite as the leader of the Labour party and Her Majesty's Opposition.'

A spokesman for the Labour Against Anti-Semitism campaign said: 'The strength of former Chief Rabbi Jonathan Sacks comments show how concerned the Jewish community is at the prospect of a Jeremy Corbyn government, and the broader Labour membership needs to respond to what is a new low for the party.

'The Labour Party cannot continue to stagger from one antisemitism crisis to another, but unfortunately that is the future of the party under the leadership of Mr Corbyn.'

The former Chief Rabbi's intervention came after footage emerged of Mr Corbyn attacking a group of British Zionists who had criticised Palestinian ambassador Manuel Hassassian. Zionism refers to the movement to create a Jewish state in the Middle East, roughly corresponding to the historical land of Israel.

In the 2013 recording, revealed last week by MailOnline, Mr Corbyn said: 'They clearly have two problems. One is they don't want to study history, and secondly, having lived in this country for a very long time, probably all of their lives, they don't understand English irony either.'

The remarks, made while the Labour leader was still an obscure backbencher, reignited the toxic row over anti-Semitism inside Labour that has rocked the party.

A Labour party spokeswoman said: 'This comparison with the race-baiting Enoch Powell is absurd and offensive.

'Jeremy Corbyn described a particular group of pro-Israel activists as Zionists, in the accurate political sense - not as a synonym or code for Jewish people.

'Jeremy Corbyn is determined to tackle anti-Semitism both within the Labour Party and in wider society, and the Labour Party is committed to rebuilding trust with the Jewish community.'

But Mr Corbyn is facing a fresh storm of controversy after MailOnline unearthed another video showing him accusing MPs of having their contributions to a debate written by the Israeli ambassador.

Speaking at a meeting of the Palestine Solidarity Campaign (PSC) in London in 2010, he accused MPs speaking in a parliamentary debate about the shooting of Turkish activists at sea by the Israeli commandos of turning up with a 'pre-prepared script'.

He said: '[British MPs] all turned up [to the debating chamber] with a pre-prepared script. I'm sure our friend Ron Prosor (the Israeli ambassador) wrote it.

'Because they all came up with the same key words. It was rather like reading a European document looking for buzz-words.

'And the buzz-words were, 'Israel's need for security'. And then 'the extremism of the people on one ship'. And 'the existence of Turkish militants on the vessel'.

'It came through in every single speech, this stuff came through.'

Jews, including the Labour MP Luciana Berger (pictured) have repeatedly demanded Mr Corbyn tackle anti-Semitism inside Labour

MailOnline has examined the transcript of the debate in question and could find no evidence that any of Mr Corbyn's 'buzz words' were mentioned by MPs.

In addition, a number of parliamentarians who spoke during the session have confirmed to MailOnline that they received no such 'pre-prepared script' or 'buzz-words' from Israeli sources.

In a statement issued last Friday night on his remarks on Zionists and irony, Mr Corbyn defended his use of language in 2013 - but said he was now more cautious.

He said he had used the term Zionists 'in the accurate political sense and not as a euphemism for Jewish people'.

He added: 'I am now more careful with how I might use the term 'Zionist' because a once self-identifying political term has been increasingly hijacked by anti-Semites as code for Jews.'

Commenting on the same remarks, a spokeswoman for Mr Corbyn said: 'This was a speech about the need to better teach the history of Israel-Palestine and about the brutality of colonialism, occupation and dispossession.

'A section of the speech that was edited out of the footage posted on YouTube sets his comments in context, he had been speaking about Zionists and non-Zionist Jews and very clearly does not go on to use Zionists as any kind of shorthand for Jews.'