Suella Braverman's incendiary speech went down well with Tory activists.
The home secretary warned of a “hurricane” of immigration which she said was sweeping the globe.
She accused Labour of supporting “open borders” and suggested migrants to the UK take the jobs of those already here.
And in a direct attack on Keir Starmer, she said “Britain would go properly woke” if he becomes prime minister.
Unlike her cabinet colleagues, Braverman delivered her speech to a packed conference hall, with Tory activists giving her a lengthy standing ovation at the end.
Her populist address also throws down the gauntlet to Rishi Sunak, who has endured a difficult conference so far and delivers his own keynote address tomorrow.
Braverman, whose parents immigrated to the UK in the 1960s from Mauritius and Kenya, told the conference: “One of the most powerful forces reshaping our world is unprecedented mass migration.
“The wind of change that carried my own parents across the globe in the 20th century was a mere gust compared to the hurricane that is coming.
“Because today, the option of moving from a poorer country to a richer one is not just a dream for billions of people. It’s an entirely realistic prospect.”
She said the Conservatives were taking measures to limit the numbers coming to the UK, and accused their opponents of having “luxury beliefs”.
“People with luxury beliefs will flock to Labour at the next election because that’s the way to get the kind of society they want,” she said.
“They like open borders. The migrants coming in won’t be taking their jobs. In fact, they are more likely to have them mowing their lawns or cleaning their homes.”
Turning her guns on Labour, Braverman said Starmer was “our secret weapon” in next year’s election.
“Imagine what would happen if he became prime minister,” she said. Luxury beliefs would reign supreme. Britain would go properly woke.”
The home secretary also defended Susan Hall, the Tory candidate to be mayor of London who has been criticised for claiming Jewish people are “frightened” of Sadiq Khan.
Braverman said: “If there’s any justice in this world, Susan Hall is going to wipe the floor with him in May.
“They’ve already started the character assassination against Sue. The distortions. The insults. The lies.
“That’s what the Labour Party always does. It prefers smears to debate.”