The recording echoes previous disparaging remarks about the working culture in Britain in a book, Britannia Unchained, that she co-authored.
In the leaked recording she lays into the British workforce for not being willing to do the necessary work to increase prosperity.
The recording was from 2019 when Truss was chief secretary to the treasury, according to the Guardian.
In the recording Truss says: “There’s a slight thing in Britain about wanting the easy answers. That’s my reflection on the election and what’s gone before it, and the referendum – we say it’s all Europe that’s causing these huge problems … it’s all these migrants causing these problems. But actually what needs to happen is more … more graft. It’s not a popular message.”
She also controversially suggested London workers were more industrious than others across Britain.
She said: “I once wrote a book about this which got mischaracterised – British workers produce less per hour than … and that’s a combination of kind of skill and application. If you look at productivity, it’s very, very different in London from the rest of the country.
“But basically … this has been a historical fact for decades. Essentially it’s partly a mindset and attitude thing, I think. It’s working culture, basically. If you go to China it’s quite different, I can assure you.”
Ms Truss added: “There’s a fundamental issue of British working culture. Essentially, if we’re going to be a richer country and a more prosperous country, that needs to change. But I don’t think people are that keen to change that.”
In the 2012 book Britannia Unchained it was suggested that British workers were the “worst idlers in the world”, although she has sought to distance herself from the controversial comments.
In the first televised head-to-head Tory leadership debate last month, Ms Truss claimed she had not written the offending chapter including the remarks and blamed her fellow author Dominic Raab instead.
Mr Raab later claimed that the authors, who also included Priti Patel and Kwasi Kwarteng, had taken “collective responsibility” for the book, adding: “It’s up to Liz to explain why she’s changed her view.”
Meanwhile a source from the Truss campaign said of the leaked audio: “These half-a-decade-old comments lack context but one thing that is as clear today as ever before is a need to boost productivity, which leads to higher wages and a better quality of life for workers right across the UK. As prime minister, Liz will deliver an economy that is high wage, high growth and low tax.”
However the shadow work and pensions secretary, Jonathan Ashworth, branded her comments “grossly offensive”.
He told the Guardian: “With wages shrinking thanks to Tory failure to bring inflation under control and years of lacklustre growth, it’s grossly offensive for Liz Truss to effectively brand British workers lazy.
“I would have hoped she had moved on from the days of her Britannia Unchained fiasco, but it seems that is the blueprint for her prospective government. Workers across the country are working all hours to keep a roof over their heads, put food on the table and provide for their families. Liz Truss should be helping working people to cope with this cost of living crises, as Labour this week outlined we would do, not peddling this offensive nonsense.”
Truss is leading Rishi Sunak in the race to be the next tory leader according to recent polls while eleven Conservative whips are backing her campaign.