Sadiq Khan highlighted his Tory rival Susan Hall’s apparent endorsement of the term “Londonistan” as he warned of the dangers of inflaming tensions sparked by the terror attacks on Israel.

The mayor said politicians had to avoid “mainstreaming hatred” at a time the fallout from the attacks on Israel and the humanitarian crisis in Gaza had sparked protests and anti-Semitic attacks in London.

Mr Khan, speaking at Mayor’s Question Time at City Hall on Thursday, said it was vital to avoid an “overspill in London” from the situation in the Middle East.

In January 2019, Ms Hall, who was selected as the Tory 2024 mayoral candidate this July, replied to a tweet from Katie Hopkins that described Mr Khan as “our nipple height mayor of Londonistan” by saying: “Thank you Katie!”

“Londonistan” is a term used to convey the idea that Muslims are taking over London. It is viewed by many as an Islamophobic trope.

Ms Hall has frequently attracted controversy about her Twitter history.

Mr Khan, who is a Muslim, was responding to a question from Ms Hall about the support available to Londoners who had lost loved ones in Israel.

Ms Hall said there was also a need to support the Muslim community in London and prevent those seeking to “exploit the crisis” and “unfairly blame ordinary Muslim families here in London for Hamas’s action”.

Mr Khan replied: “I make this point, and I make this point neutrally: that when you describe our great city as ‘Londonistan’, you can understand why Muslims are concerned, in relation to Islamophobic attacks and hate crime.

“That is why all of us, me included, have got to be cognisant of the consequences of words. Because they can create an environment where, whether it is anti-Semitic attacks, or Islamophobic attacks or other forms of hate crime take place.

“I have always sought, as both the mayor of this great city, and also as a parliamentarian before that, to understand the importance of not inadvertently mainstreaming hatred that must exist never more than at the periphery.”

Last month Ms Hall, who did not respond to the mayor’s reference, told LBC she did not recall sending the tweet. In a subsequent interview with the Financial Times, she said she did not know “Londonistan” was a pejorative term that implied too many Muslims lived in the capital.

Speaking at Mayor’s Question Time on Thursday, Ms Hall, who attended a vigil in London on Monday, said the situation in Israel was “horrific and heart-breaking”.

She said: “We stand with Israel in defending itself from this appalling terrorist attack.

“This is an issue that goes beyond politics and, no matter our political differences, I do welcome the work that you have done with the Met police in providing further reassurance to our communities, and I do mean that.”

She said two Harrow residents were among the 17 Britons missing or feared dead. Ms Hall is a former Harrow council leader.

Ms Hall withdrew a question that she was planning to ask Mr Khan that asked whether “things are going well under your mayoralty?”

It is understood she wanted to avoid a petty political spat at a time the situation in Israel and Gaza is causing such concern.

Mr Khan, in his opening remarks at Mayor’s Question Time, said: “There can be no justification for what Hamas did.”

He said this was consistent with his views on a “two-state solution”.

He said: “I think it is consistent to be pro-Palestine as an independent state, and pro Palestinian rights, and condemn unequivocally what happened over the weekend. I don’t think these issues should be conflated.

“You can also be concerned about the response from the Israeli government to Gaza – cutting off food, water and humanitarian supplies.

“It’s really important we don’t allow hate crime against Jewish people in this city or this country or around the globe.”

He said: “I want to place on record my condemnation of the sickening terrorist attacks committed by Hamas against Israel over the weekend. There is no justification for the murder of innocent people.

“I am acutely aware that these events have left Jewish Londoners feeling shaken and fearful. In fact, I’m yet to meet a single Jewish Londoner who hasn’t been affected.

“As well as Jewish Londoners, there are also many Palestinian, Muslim and Christian Londoners who are deeply worried about the safety of friends, family and loved ones.”

Mr Khan said he had written to Foreign Secretary James Cleverly to ask that the UK Government supports calls from the World Health Organisation and United Nations “to establish humanitarian access to and from Gaza to allow the safe passage of essential supplies and humanitarian access”.

He said London would take a “zero tolerance approach” to all forms of hate crime. Asked why police did not appear to intervene during a protest outside the Israeli embassy in Kensington, he said that officers often gathered evidence but intervened later.

City Hall has been lit at night in the colours of the Israeli flag. Asked why the flag itself was not flying from outside City Hall as a mark of solidarity and respect, Mr Khan said the Greater London Authority was following Government guidance to fly the flag until October 10, and said it was “nothing more” than staff not working over the weekend for any failure to do so.

Mr Khan said: “London is the most diverse city in the world, and I urge Londoners to look out for each other in the coming days and weeks.

“There are forces that will seek to exploit the situation in the Middle East in an attempt to sow the seeds of division here. We cannot and must not let them.”