Keir Starmer was met with an eruption of applause after he savaged racists who graffiti Chinese takeaways and call for our neighbours to be deported.
The PM said those who paint "graffiti telling a Chinese takeaway owner to go home, that's not pride, that's racism". And he criticised those who imply that "people cannot be English or British because of the colour of their skin".
In a powerful message, he hit out at racists who target people who have lived in Britain for generations, who work in our schools, hospitals and businesses, branding them "an enemy of national renewal".
He said: "If you say they should now be deported, then mark my words, we will fight you with everything we have."
Elsewhere in his speech, Mr Starmer sought to reclaim British flags from Reform and vowed to “never surrender them”.
Welsh, English, Union Jack and Scottish flags were given out to supporters at Labour party conference in Liverpool, with the PM urging members to wave them to show they “belong to all of us”. His call came just minutes after Mr Starmer had claimed Nigel Farage “doesn’t like Britain” and “doesn’t believe in Britain”.
Encouraging the waving of flags, he said: “Britain stands at a fork in the road. But at the end of the road, there will be a new country, a land of dignity and respect. Our flags flying proudly as we celebrate difference and oppose racism.
"Let's fly all our flags conference. Because they are flags. They belong to all of us, and we will never surrender them."
He also said throwing bricks in an apparent protest is "not legitimate - that is thuggery". The Prime Minister said: "There is a line, a moral line, and it isn't just (Reform UK leader Nigel) Farage who crosses it.
"There are also people who should know better, sowing fear and discord across our country, and then, when we call that out, they pretend we're criticising reasonable concerns about immigration.
"We have seen that trick, conference, so let us spell it out, once and for all: Controlling migration is a reasonable goal, but if you throw bricks and smash up private property, that's not legitimate - that is thuggery."