Ms Hall told the Mayor: “You have made previous assertions that London does not have the same type of grooming gangs,” as those seen in the towns she listed.

He added: “What I have said is echoing the words of the commissioner now, and the assistant commissioner […] they have both explained there are serious issues in relation to child sexual exploitation.”

In June this year, the Mayor told Assembly Members: “There are no reported cases and also no indication of the grooming gangs that she is concerned about in London.”

Earlier in the year, Mr Khan repeatedly asked Ms Hall to explain “what she means” by grooming gangs, prompting accusations from critics that he was “stonewalling” direct questions on child sexual exploitation.

At the time, the Mayor said: “The situation in London in relation to young people being groomed is different to other parts of the country. What we have in London is young people being groomed – to use your word, not mine – to be used in county lines.”

In Thursday’s meeting, Mr Khan repeated his claim that child exploitation in the capital was centered around county lines drug dealing gangs.

Ms Hall said she would continue to raise the issue, telling the Assembly: “Every day that goes by, other girls, and sometimes boys, are groomed. Every single day.”

She added: “I still don’t think you realise the impact of you being so rude to me just under a year ago, when you said ‘what does the member mean, what is she talking about?'”

Ms Hall went on: “You knew damn well what I was talking about, because it has been going on for years. You’re the Mayor of this great city, it’s going on in London, and every day that goes by where we don’t have an inquiry in place, these girls and sometimes boys are suffering.

“And yet when they look at your comments on it, you don’t take it seriously enough.”

She repeated calls for a London-specific inquiry into grooming gangs. A motion put forward by Conservative Assembly Members for a funded inquiry was voted down by Labour members earlier this year.

In his response, Mr Khan blamed the previous government for failing to implement the Jay Report and said he welcomed the Government’s decision to back a national inquiry.

Susan Hall AM, speaking exclusively to the Express, said: “He avoids the question, he runs the clock down, and he desperately tries to change the narrative on grooming gangs to escape the fact that he has shamefully neglected his responsibility to the victims.

“This is a disgrace – survivors deserve far better and I’m not going to stop fighting this Mayor to get them that.”

Earlier this year, an investigation by the Daily Express identified 24 cases across the capital from council documents, reviews into deaths and historic media reports.

The investigation found that a number of children who had been subjected to sexual abuse may have been victims of grooming gangs, based on expert analysis.