Kwasi Kwarteng has said he "had to go" to a private champagne bash with bankers on the day of the mini-Budget but admitted "it probably wasn't the best day to go".
The embattled Chancellor insisted he only attended the boozy do for 15 minutes and added: "I totally get how it looks."
Labour has demanded a list of attendees at the event, which was reportedly held at the London home of a Conservative donor.
Mr Kwarteng was said to have given insights about his plans to hedge fund bosses at the event who may have profited from the pound's fall. His team denied this outright.
The Chancellor was grilled about the event in a bruising interview after he confirmed the Tories would ditch their controversial plans to axe the 45p income tax rate for the richest Brits.
Asked by LBC why he went, Mr Kwarteng said: I spent, I think, quarter-of-an-hour there, maybe a bit longer, and it was a party event.
"We had party events all the time."
Host Nick Ferrari interrupted to clarify if it was a Conservative Party event.
The top Tory replied: " Conservative Party sorry... A Conservative Party event, which had been booked in for a few weeks actually.
"And as you remember, I mean, it was a very difficult time because we had her Majesty's passing.
"We had her funeral, there were dates moving around and the dates of that seemed to coincide with the mini-Budget."
Asked if he would have gone with hindsight, he said: I think it was a difficult call, and I totally get how it looks.
"I just feel that it was something that I was signed up to do and I had to do."
Pressed again on whether he should have gone, he said: "With hindsight, it probably wasn't the best day to go."
The Chancellor was forced into a massive U-turn this morning after admitting plans borrow billions to axe the 45% top income tax rate had become a "terrible distraction" amid threats of a Tory rebellion.
It came only only hours before he was due to give a speech to Tory conference vowing to "stay the course" on his mini-Budget.
