Members of the ruling Labour administration denounced their opponents' actions as "shameful" and accused them of showing a lack of respect to victims of racist and xenophobic abuse in the wake of the European Union referendum.
But Conservative councillors defended their behaviour on the night, claiming it was Labour councillors who were sending the wrong message to those on the receiving end of hate-filled taunts or violence.
The row flared over a seemingly innocuous motion tabled by Labour councillors at the end of a council meeting on Tuesday, July 19.
The motion, aimed at providing reassurance amid a reported surge in hate crime following the referendum, called on councillors to condemn racism, xenophobia and other hate crimes.
While Conservative councillors said they agreed with the essence of the motion, they took umbrage at the final paragraph, which stated: "We reassure all people living in Hounslow that they are valued members of our community."
They felt it was important to clarify that those responsible for hate crime, and other criminals, were very much not valued members of the community.
Their amendment read: "We reassure all people who live in the borough that they are valued members of the community apart from those who are intolerant of diversity, seek to undermine democratic government and who do not accept the authority of the British legal system."
Walkout showed 'utter disrespect' to worried residents
Four Conservative councillors walked out during the debate in protest as they believed this amendment was not given the consideration it deserved.
Those Tory members remaining abstained from the subsequent vote, but the original motion was passed.
Labour councillor Sue Sampson, Hounslow Council's cabinet member for community safety, said: "I'm extremely disappointed that the Conservative Group did not support our motion. Nearly half of the Tory group decided to abandon their duties by shamefully walking out of the debate before it was over."
She added that those who walked out had shown "utter disrespect" to the many residents who had raised concerns about hate crime since the referendum.
'Limits to free speech and antisocial behaviour'
The four councillors who walked out were: Sheila O'Reilly, Robert Oulds, Samantha Davies and Adrian Lee.
Councillor Sam Hearn, deputy leader of Hounslow Conservative Group, defended their actions.
He said: "Members of Hounslow Conservative Group strongly believe that those in the borough who suffer from hate crimes can receive little comfort from a statement by the council that does not make it crystal clear that those with unacceptable views are not 'valued members of the community'.
"In a free society there are limits, under the law, to free speech and antisocial behaviour that can and should never be condoned."
Tory councillor stands by claims of Hounslow 'no-go areas'
Labour councillors also called on Cllr O'Reilly to defend comments she had made to the Daily Mail during the referendum campaign.
The newspaper quoted her in June as saying the increase in population had put pressure on local services, and there were parts of the borough where she would "not be happy going even in daylight".
Cllr O'Reilly told getwestlondon she stood by those comments, despite Labour members insisting there were no such "no-go areas".
She said it could be "quite intimidating" walking around Hounslow town centre and the shopping parade in Hounslow West, where she claimed street drinkers were a real problem.
She also said she was "very sceptical" there was any link between Brexit and the rise in hate crime which has been reported in London.
The motion on hate crime in full
"We agree with the Mayor of London, Sadiq Khan, that we all have a responsibility following the European Union referendum result to heal the divisions that have emerged, and to focus on that which unites us, rather than that which divides us.
"We are proud to live in a diverse and tolerant society. Racism, xenophobia and hate crimes have no place in our country.
"This council condemns racism, xenophobia and hate crimes unequivocally. We will not allow hate to become acceptable.
"This council will continue to work with the police and our partners to fight and prevent racism, xenophobia and hate crime across Hounslow.
"We reassure all people living in Hounslow that they are valued members of our community."
* this is the original motion, as approved, without the amendment proposed by Conservative councillors