Labour is to launch more adverts attacking Rishi Sunak by blaming him for “crashing the economy”, despite criticism from within the party.
The initial ad, which accused the Prime Minister of not wanting child sex abusers to go to prison, caused unease among the Shadow Cabinet.
But frontbencher Emily Thornberry continued to defend the ad, which colleagues including shadow culture secretary Lucy Powell have declined to endorse.
“And if the answer to both of those things is yes, then I don’t see any reason why we can’t criticise that person individually.”
She said if Mr Sunak “really thought that it was so important, he would do something about it”.
Sir Keir Starmer also defied critics of the advert, saying he made “absolutely zero apologies” for the campaign regardless of how “squeamish” it made people feel.
Writing in the Daily Mail, the Labour leader said he refused “to just stand by or avoid calling this what it is”.
Senior party figures including former home secretary Lord David Blunkett called for the ad to be withdrawn, arguing that Labour is better than the “gutter” politics.
Further adverts scheduled to drop ahead of the May local elections are to include one suggesting Mr Sunak thinks it is right that the public is paying for the “Conservatives crashing the economy” through higher housing costs.
Ms Thornberry was challenged over Sir Keir’s role as a member of the Sentencing Council when it set out guidelines in 2012 suggesting that not all child sex abusers should automatically be jailed.
Asked whether Sir Keir, the then-director of public prosecutions, objected to the guidelines at the time, she said: “I don’t know the details of what the exact guidance is in relation to the Sentencing Council, but I do know this, that it is open to Parliament to set minimum and maximum sentences.”
She said it should be the “default position” that an adult convicted of sexually assaulting a child will go to prison.
“What we need to do is we need to look at it from the very beginning to the very end of the criminal justice system.
“If we had more community police officers on the street, which we do commit to and we have a clear idea of where the funding comes from in relation to that, we would be able to catch people earlier.”
The row centres on a tweet in which Labour highlighted analysis of official data and said that under the Tories “4,500 adults convicted of sexually assaulting children under-16 served no prison time”.
Alongside a photo of the Prime Minister, it read: “Do you think adults convicted of sexually assaulting children should go to prison? Rishi Sunak doesn’t.”
Judges and magistrates, rather than the prime minister of the day, are responsible for handing out sentences.
The figures Labour highlighted cover the period since 2010, five years before Mr Sunak entered Parliament. He did not become Prime Minister until October last year.