A Labour frontbencher has clashed with Jeremy Corbyn’s right hand man over the party’s attack adverts in a heated televised exchange.

Lisa Nandy, the shadow levelling-up secretary, said she would take “no lectures” from John McDonnell, who was Jeremy Corbyn’s shadow chancellor, after he criticised the recent publicity campaign.

Labour faced a backlash over a social media post a fortnight ago suggesting Rishi Sunak did not want to jail those convicted of child sex offences. It has since doubled down with further personal criticisms of Mr Sunak.

The original tweet, which pointed to Ministry of Justice data showing a total of 4,500 adults convicted of sexually assaulting children had not received jail sentences since 2010, read: “Do you think adults convicted of sexually assaulting children should go to prison? Rishi Sunak doesn’t.”

Appearing on ITV’s Peston, Mr McDonnell told Ms Nandy: “I know you, Lisa. This is not you, this is not you. You never go for the person in this individual way, you go for the facts and you go for the policy issue.”

When the shadow minister interjected “the facts are there”, he replied: “The facts are there, but the reference with regard to Rishi is unacceptable. Take Michelle Obama’s advice, ‘when they go low… we go high’.

“We are better than them and you know that, and you are as well.”

Ms Nandy argued Mr Sunak must “take responsibility” for the Conservatives’ record on crime and sentencing, going on to criticise Mr McDonnell for his role in Labour’s top team under Mr Corbyn amid its anti-Semitism crisis.

She told him: “You were a senior member of the Labour Party when we were found to have breached equalities law by the Equality and Human Rights Commission and brought us to our lowest point in our 100-year history.

“So I will not take lessons from you about civility in politics.”

Mr McDonnell countered the party “held our hands up” over anti-Semitism, adding: “But on this, you don’t do this. This is not Labour politics. We’re better than this… It undermines our argument.”

Later in the programme, Ms Nandy was pressed on whether she felt the original tweet represented the Prime Minister’s actual personal views.

“I don’t know,” she said. “No, I don’t know, and actually it’s up to him to say so, isn’t it? If he believes that people who abuse children should go to prison, he should do something about the broken justice system that he’s presided over.”

Earlier this week Jess Phillips, the shadow domestic violence minister, told a podcast she was “f---ing furious” over the Government’s record on abuse and the attack on Mr Sunak was “not hard enough”.

The main parties’ records on crime have become one of the most prominent political debates in recent weeks, with the row dominating Prime Minister’s Questions on Wednesday.

Mr Sunak dubbed Sir Keir Starmer, the Labour leader, “Sir Softie” in a jibe at his time as Director of Public Prosecutions (DPP).

It has also emerged Sir Keir was on the Sentencing Council in 2012 when it agreed child sex abuse should not get an automatic prison sentence.