Rory Stewart was the “marginal loser” in Tuesday’s Tory leadership debate, Iain Duncan Smith has said.
The former Conservative Party leader, who is backing Boris Johnson, told talkRADIO’s Julia Hartley-Brewer: “There was a marginal loser because I think Rory Stewart for the first time came under aggressive attacks and he did not know how to deal with it.
“That is a good example of not having real experience of dealing with hard questions.”
Mr Duncan Smith said he struggled to watch Tuesday's BBC debate because of the “awkward” format.
The five remaining MPs face a third vote on Wednesday
“The semi-circle position meant that the people in the middle stared straight at the camera but those on the left and right had to look over their shoulders.
“Politicians do their work on their feet, you don’t get passion and energy when people are awkwardly sat on stupid stools. People talked over each other, which is a killer on TV, and that became a shambles. The format sent the whole thing into a bit of chaos.”
The five remaining contenders - Mr Johnson, Mr Stewart, Jeremy Hunt, Michael Gove, and Sajid Javid - will face a third vote by Conservative MPs on Wednesday afternoon.
The leadership hopeful with the least support will be eliminated before more voting on Thursday.
As frontrunner, Mr Johnson is expected to reach the final run-off, which will see some 160,000 Tory members select the next Prime Minister.
However, Mr Duncan Smith said he was not sure who would join him.
“I think up until recently I would have said Jeremy Hunt would have been the one behind [Boris] but at the moment, it is a bit of a scramble.