Former chancellor Kwasi Kwarteng has admitted he and Liz Truss "blew it" and got "carried away" with bringing in sweeping economic reforms.
The Tory MP said the low-tax, small-state plans they had were "very exciting" and he was fully behind them but accepts that the way they were executed was their downfall.
Mr Kwarteng announced his "mini" budget just 17 days after his good friend Ms Truss became PM and made him chancellor, which caused the markets to crash and him to be sacked - before Ms Truss was also forced to step down.
"It was very exciting, you felt you were part of a project," he told the FT Weekend Magazine.
As soon as she became PM, Ms Truss said she did not want any opinion polling as she felt politicians were obsessed with "optics".
Despite advisers warning her and Mr Kwarteng that their plans would be seen as a "budget for the rich", they were ignored.
Mr Kwarteng added: "People got carried away, myself included. There was no tactical subtlety whatsoever."
He still believes the goal was correct but admitted: "Where we fell woefully short was to have a tactical plan."
As the economic turmoil continued, despite the government U-turning on some of the recently announced policies, Mr Kwarteng went to IMF meetings in Washington as he did not want to cause more panic by not attending.
But he was called back early after, he and his allies believe, Cabinet Secretary Simon Case managed to persuade Ms Truss she had to reverse some of the measures to avoid economic ruin.