LBC presenter Nick Ferrari threatened to “terminate” his interview with a government minister as the pair clashed over the definition of a working person.

Labour’s election manifesto pledged not to put up taxes on “working people”, but senior party figures have repeatedly struggled to say what that actually means.

Prime minister Keir Starmer suggested in a Sky News interview last night that it did not include people who make money from shares or property, such as landlords.

However, No.10 later clarified that people with small shareholdings could still be working people.

On LBC this morning, Ferrari asked Treasury minister James Murray: “What is a working person?”

The minister replied: “A working person is someone who earns their income from going out to work, and we’re very clear about the importance of protecting working people, which is why we made the promise in our manifesto about the rates around income tax, National Insurance and VAT.”

The presenter then asked: “Is a landlord a working person then, Mr Murray?”

The minister said: “Well it depends where people earn their money from, and that’s why the focus of our commitment is around working people.”

Growing more impatient, Ferrari said: “You’re a very bright bloke. You know how a landlord makes his or her money. Is a landlord a working person?”

As Murray struggled to answer, the veteran broadcaster said: “I’m sorry, perhaps we’re having technical problems. Perhaps you never heard the question. It’s a yes or no, sir. Is a landlord a working person?”

The minister told him: “It depends on how people earn their money. The focus is on people who go out to work.”

Ferrari then asked: “Are you having problems hearing me? Because we have had enormous technical issues. Because you clearly know how a landlord makes their money. Does that mean they’re a working person?”

Murray said: “As I said Nick, our focus in terms of working people is on people who go out …”

Interrupting him again, the presenter said: “I’m terribly sorry, I’m going to hold you to a yes or no here, and you are a very bright man, and we’ve spoken in the past.

“Please don’t dance around this question. Mr Murray, I don’t need to tell you how a landlord makes their money, or indeed how a shareholder makes their money. Are they working people?”

The minister replied: “But Nick, it’s not about individual people we’re talking about, we’re talking about how people earn their money. And when we’re talking about working people, it’s about people who earn their income by going out to work every day.”

Ferrari then said: “So does a landlord go out to work every day? I think I might terminate this interview. I’ll try one last time. We have gone round and round the houses. I hope you’re informed about what the prime minister has said overnight. What has the prime minister said on this?”

The minister replied: “What the prime minister has said is that the definition of working people is a wide one, but he talked about who he has in mind when he’s making decisions, and he talked about people who go out to work every day, who might have a little bit of savings, but who don’t have enough savings so that if they are faced with a big challenge in their lives they can’t just write a cheque to make it go away.”

The presenter then said: “But as regards to landlords and shareholders, Keir Starmer suggested they are not working people. Do you concur?”

The minister repliedf: “I think the point that he was making was that where people earn their money from is important in terms of our protecting working people commitment. When we’re talking about protecting working people, we’re taking about people who go out to work.”

The row came as chancellor Rachel Reeves prepares to deliver her first Budget, in which she is expected to hike taxes and cut spending in an attempt to raise an extra £40 billion.