Sir Keir Starmer has pitted Labour directly against Reform UK as he warned his party was in a battle for the "soul" of Britain.
The Prime Minister used his leader's speech at the Labour Party Conference in Liverpool to take aim at Nigel Farage and the "politics of grievance".
He said Farage "doesn't like Britain" and wants to create “a competition of victims”.
Instead, Sir Keir promised "a land of dignity and respect".
"We can all see these snake oil merchants, on the right, on the left, but be in no doubt, conference, none of them have any interest in national renewal, because decline is good for their business,” he told delegates.
"When was the last time you heard Nigel Farage say anything positive about Britain's future? "He can't. He doesn't like Britain, doesn't believe in Britain, wants you to doubt it as much as he does.
"And so he resorts to grievance. They all do it. They want to turn this country, this proud, self-reliant country, into a competition of victims."
After a turbulent period for his leadership and the prospect of a Budget in November, which could see tax hikes and spending squeezes, Sir Keir warned that further difficult choices will be needed on the UK’s path to "national renewal".
The speech comes at a challenging moment for the Prime Minister following speculation about a challenge to his leadership fuelled by criticism from Andy Burnham - although the Mayor of Greater Manchester insisted on Monday he believes Sir Keir is the right man for the job.
Meanwhile, Reform continues to enjoy a comfortable lead in polls, and Labour faces a battle to keep its promises on taxation, spending and immigration.
The Prime Minister said: "We can all see our country faces a choice, a defining choice.
"Britain stands at a fork in the road. We can choose decency. Or we can choose division.
"Renewal or decline. A country - proud of its values, in control of its future or one that succumbs, against the grain of our history, to the politics of grievance."
Sir Keir compared the challenge facing Labour now to Clement Attlee's administration in 1945 as it rebuilt Britain from the ruins of the Second World War.
"It is a test,” the Prime Minister said.
“A fight for the soul of our country, every bit as big as rebuilding Britain after the war, and we must all rise to this challenge.
"And yet we need to be clear that our path, the path of renewal, it's long, it's difficult, it requires decisions that are not cost-free or easy. Decisions that will not always be comfortable for our party.
"Yet at the end of this hard road there will be a new country, a fairer country, a land of dignity and respect.
"Everyone seen, everyone valued, wealth creation in every single community, working people in control of their public services, the mindless bureaucracy that chokes enterprise, removed - so we can build and keep on building."
Sir Keir said he believes Britain can "unite around a common good".
"That's my ambition, the purpose of this government," he said.
"End decline, reform our public services, grow our economy from the grassroots."
The PM promised to scrap the target to get 50% of young people into university and instead invest in apprenticeships to get young people into skilled jobs.
Sir Keir also vowed a technological revolution for the NHS, with a new "online hospital" for patients in England aimed at cutting waiting lists and providing quicker treatment and advice.
The scheme, which will begin operating in 2027, will deliver up to 8.5 million extra NHS appointments in its first three years, Labour claimed.
Those who use the service will be able to access and track prescriptions, be referred for scans and tests, and receive clinical advice on managing their condition.
Patients who require a physical test or a procedure will be able to book them on the NHS app at a nearby hospital, surgical hub or community diagnostic centre.
Ahead of the Prime Minister's speech, Health Secretary Wes Streeting told delegates that Reform would put the NHS at risk.
He said: "We are in the fight of our lives, not just for the NHS or even for the survival of this Government, but for everything we believe in.
"It is a battle of progressives against reactionaries, patriotism versus nationalism, hope not hate."
