The Conservative Party has suspended a number of members pending an investigation after a dossier suggested they had posted or endorsed Islamophobic and racist material online.
Twenty-five sitting and former Tory councillors were said to be among those named in the documents, which were obtained by The Guardian.
The party said all of those found to be Tory members had been “suspended immediately, pending an investigation”.
“The swift action we take on not just anti-Muslim discrimination, but discrimination of any kind is testament to the seriousness with which we take such issues,” a spokeswoman said.
“The Conservative Party will never stand by when it comes to prejudice and discrimination of any kind.
“That’s why we are already establishing the terms of an investigation to make sure that such instances are isolated and robust processes are in place to stamp them out as and when they occur.”
It is understood not all the names provided in the dossier are members of the Tory Party, but the party was unable to say how many members had been suspended.
The disclosure will increase pressure on Boris Johnson to hold an independent inquiry into Islamophobia in the party, rather than a broader investigation into prejudice within its ranks.
Shadow equalities minister Naz Shah said: “The Conservative Party is rife with Islamophobia, racism and bigotry from top to bottom, but we have no faith that Boris Johnson will do anything about it.
“Johnson’s comments about Muslim women looking like ‘bank robbers’ and ‘letter boxes’ were linked to a 375% rise in anti-Muslim hate crime, and polls show a majority of Conservative Party members hold Islamophobic views.
“Boris Johnson must commit to a full independent inquiry into Islamophobia and stop pretending it doesn’t exist in his party.”
The allegations come just days after a former adviser to Boris Johnson faced calls to be removed as an election candidate after Labour accused him of displaying “disgusting racism” in an article written almost 17 years ago.
Anthony Browne, a Conservative candidate for South Cambridgeshire, made comments blaming immigrants for bringing germs and HIV to the UK and accused Muslims of having divided loyalties, according to The Guardian.
In an article on The Spectator website, dated January 2003, Mr Browne wrote: “It is not through letting in terrorists that the government’s policy of mass migration – especially from the third world – will claim the most lives. It is through letting in too many germs.”