A mosque in Zac Goldsmith's constituency has branded his campaign "deeply irresponsible" and warned his approach risks dividing communities in London.
The Conservative party's London mayoral candidate has typically enjoyed a good relationship with Kingston mosque and the Richmond Park MP even held a surgery for constituents at its community centre as recently as January.
But on Monday night, the mosque released a strongly-worded statement and said its members were concerned about the tone of his mayoral campaign, described in a press release as "increasingly toxic [in] nature".
The mosque statement said that although members of the community understood the need to confront national security challenges, it was wrong to associate this with his Labour rival Sadiq Khan because he is Muslim.
"The singling out of rival Sadiq Khan MP because of his Muslim faith, as pointed out by a number of senior Conservative Muslim politicians, and the subsequent insinuation that he may be soft on terror as a result of it, is extremely troubling," the statement read.
"Muslim communities must not be used as pawns as part of a wider political strategy to win elections. It is deeply irresponsible and rather than unifying diverse communities it will undermine the social fabric that makes London such a great city."
The mosque also called on Goldsmith to apologise for some of his previous comments which also provoked concern from Operation Black Vote.
"In the final days leading up to polling day we strongly urge Zac and his team to express their regret for the damage that has been done and to return to discussing issues that matter the most to Londoners, in a balanced and fair manner, and in keeping with the spirit of a united, prosperous and diverse London," the statement added.
The reaction from the mosque came after Goldsmith was criticised for an opinion piece he wrote in the Mail on Sunday illustrated with a photo of the bus destroyed in the 7/7 bombings.
It follows on from a campaign that has seen Conservative MPs question Khan's judgement and accuse him of sharing a platform on a number of occasions with extremists.
Goldsmith responded to the criticism from the mosque in an interview with LBC on Tuesday morning. The Conservative candidate said he had contacted mosque leaders and was told they were reacting to the column in the Mail on Sunday.
He said that he did not choose the image or headline and added: "When I saw the image I felt it was inappropriate. I let that be known publicly and privately."
BuzzFeed News asked Goldsmith's campaign team on Sunday whether they would complain to the Mail on Sunday about the use of the pictures but they did not respond to a request for comment.