Yvette Cooper has branded those in Reform UK as "plastic patriots" as she took aim at the party's foreign policy.
The Foreign Secretary said the British people had to choose between Labour and the "right-wing".
"There is a choice between a Labour foreign policy, rooted in our belief that strength at home depends on our partnerships abroad," Yvette Cooper said.
"And whatever chaotic right-wing ideology we end up facing at the next election, with politicians who are happy for us to surrender our national interests or slide into isolation."
Ms Cooper added that Labour was "standing up to Putin" while Nigel Farage "calls him the leader he most admires".
"While we are strengthening the Nato alliance, they trot out Russian propaganda claiming Nato caused the war," Ms Cooper said.
"And while we opened our hearts and our homes to Ukrainian children, their policy is to turn them away."
The Foreign Secretary added that those in Labour were "proud to be British, proud of our values and we know what our flag really means".
Rachel Reeves received a loud applause during her speech | PAMs Cooper's speech was followed later in the day by Chancellor Rachel Reeves who spoke on her own band of patriotism.
She said: "I'll tell you about patriotism".
"It's about the strength of our military and the security of our borders absolutely," Ms Reeves added.
"But it goes well beyond that."
Yvette Cooper receiving applause after her speech
|PA
Ms Reeves continued to outline her party's stance on patriotism before swiping Reform UK.
She said Nigel Farage's party is "willing to exploit every division and distort every challenge we face".
"Building a fairer, more prosperous Britain, that is our patriotic vision, those are our Labour values, those are our British values, and we will fight for them," the Chancellor added.
That wasn't the end of her attacks on Reform.
"The single greatest threat to our way of life and to the living standards of working people, is the agenda of Nigel Farage and the Reform party," she said.
"Whatever falsehoods they push, whatever easy answers they peddle, however willing they are to tear communities and families apart.
"They are not on the side of working people."
The Tories weren't immune from attacks with Ms Cooper earlier saying her party was working to mend relationships after the Conservatives "trashed our reputation abroad".
She said Sir Keir Starmer had "transformed" relationships with the European Union and a "special relationship" with the US, which was continuing to grow.
It was a common theme found in various speeches, including by Ms Reeves, who, on multiple occasions, said there was a clear difference between her party and the Conservatives.
"And never let anyone tell you there’s no difference between a Labour Government and a Tory Government," she said.
However, Ms Reeves failed to reference Tory leader Kemi Badenoch even once in her speech.