Sir Keir Starmer secured union and business backing for his leader’s speech, amid claims that heckling from members showed Labour is “preoccupied fighting amongst themselves”.

Frances O’Grady, general secretary of the TUC, said: “Keir’s speech today shows that Labour has a plan for fixing the cost of living crisis, for delivering decent work and pay, and for giving our children a brighter future.”

Unison general secretary Christina McAnea said: “Keir set out a new vision for the party and a new vision for the country.”

She added: “Keir’s speech shows that Labour in power could bring hope to the many families forgotten by this Government. This is a serious plan for change.”

But Unite’s national officer Rob MacGregor, speaking for the union, suggested Sir Keir still had a little way to go to convince him.

He said: “If you’re a Unite member worried about the cost of living crisis, empty petrol pumps, abhorrent fire and rehire in our workplaces and the end of furlough just hours away, there wasn’t much for you in this speech.

“We needed to hear a Labour leader who is as angry as we are about the harm being done to our workers, and as determined as Unite to stand up against abusive employers. We’re clearly not there yet.”

Paddy Lillis, general secretary of Usdaw, said: “Keir Starmer today made clear Labour is the party of working people, explaining that he is of working people and for working people.”

Momentum co-chairman Andrew Scattergood said: “Starmer’s speech identified a lot of problems but offered very few solutions.”

Conservative Party chairman Oliver Dowden claimed Labour was “more divided than ever and has no plan”, adding: “Labour spent five days talking to themselves about themselves instead of to the country.

“From resignations in the middle of their own conference, to their union backers deserting them, to disrupting their leader’s speech, Labour are too preoccupied fighting amongst themselves to put forward a plan for our country.”

From a business perspective, CBI director general Tony Danker said: “The Labour Party has taken an important step forward by outlining an agenda where businesses can find common ground.

“Its ambitions to decarbonise the economy and build a better future for everyone through improving education are shared by business.

“Lifelong learning is the bedrock of productivity, growth, and in turn, rising wages.”

Shevaun Haviland, director general of the British Chambers of Commerce, said: “Businesses will welcome the focus on digital skills, investment in R&D and the need to make Brexit work.

“However, despite the warm rhetoric, what firms really need are concrete, costed proposals and meaningful detail on delivery.”

Questions over whether the speech echoed former Labour leader Tony Blair were also dismissed, with shadow international trade secretary Emily Thornberry insisting: “No. I thought it was very Keir. Genuinely.”

Shadow health secretary Jonathan Ashworth said Sir Keir’s first in-person conference speech as leader was the “finest” he had seen from a Labour chief in a decade.

He told the PA news agency: “I thought it was a speech of substance and I think Keir Starmer can leave this conference with his head held high.

“This is a party that is changing. This is a party which is united behind Keir Starmer.”

Asked about the hecklers, Mr Ashworth said: “It was underwhelming. You see, the thing is, Keir, I thought, demonstrated a razor-sharp wit in dealing with them.”

SNP Westminster deputy leader Kirsten Oswald said the speech showed how “profoundly out of touch” Sir Keir is with “what’s actually happening in Scotland”.

GMB general secretary Gary Smith said: “We need a Labour government, but power isn’t going to be handed to Keir Starmer on a plate, he’s got to go and win it by reaching out to workers and communities who are suffering under Boris Johnson’s leadership, and his campaign must start now.”

Manuel Cortes, general secretary of the Transport Salaried Staffs’ Association, said Sir Keir was right to highlight the cost-of-living crisis and Tory “ineptitude”.

He added: “People from all walks of life are struggling and this is set to get worse as inflation rises, furlough ends and the Government fiddles while Rome burns.”