The broadcaster cancelled Tuesday evening’s event with a day’s notice after sources in Mr Sunak’s camp suggested he will only do further TV confrontations if he succeeds in making it to the final two candidates.
A statement from Sky News read: “Tuesday evening’s live television debate on Sky News between the Conservative Party leadership candidates has been cancelled.
Conservative MPs are said to be concerned about the damage the debates are doing to the image of the Conservative Party, exposing disagreements and splits within the party
Sky News statement
“Two of the three candidates currently leading in the MPs’ ballots – Rishi Sunak and Liz Truss – have confirmed to Sky News that they do not want to take part.
“Conservative MPs are said to be concerned about the damage the debates are doing to the image of the Conservative Party, exposing disagreements and splits within the party.
“Both are very welcome to take part in future Sky News televised debates.”
The second televised debate, held on Sunday by ITV, saw Mr Sunak engage in furious exchanges with both Foreign Secretary Ms Truss and trade minister Penny Mordaunt, who completes the trio of frontrunners vying for No 10.
The former chancellor accused Ms Truss of peddling “something-for-nothing” economics after she said he was choking off growth by raising taxes to their highest level in 70 years.
Mr Sunak said even former Labour leader Jeremy Corbyn did not advocate the sort of loosening of the fiscal rules being proposed by Ms Mordaunt.
On Monday morning Mr Sunak and Ms Truss’s teams told Sky they do not want to take part in the scheduled debate.
This Conservative 'leadership' contest is so scarily embarrassing they’ve pulled out of the debate - so you can’t see them fighting like rats in a sack
Deputy Labour leader Angela Rayner
One source on Mr Sunak’s team said: “We are very happy to do more debates if we are lucky enough to get to the next stage, including Sky News.”
They argued that it does not represent a change in thinking because the former chancellor’s campaign never confirmed with Sky that he would be taking part.
Ms Truss’s team said the Foreign Secretary will participate in any TV debate that all the other candidates sign up to.
The rivals took part in a private hustings for the 1922 Committee of Tory backbenchers before Conservative MPs vote again on Monday for their favoured candidate, with the one with the least support being eliminated.
Asked if she had recovered from Sunday’s leadership debate as she prepared to enter the 1922 hustings, Ms Truss said: “Just about.”
Deputy Labour leader Angela Rayner said: “This Conservative ‘leadership’ contest is so scarily embarrassing they’ve pulled out of the debate – so you can’t see them fighting like rats in a sack.”
A source on Ms Mordaunt’s campaign said: “Media scrutiny is important in this contest. Penny has done broadcast and allowed time for journalists to ask questions at her launch.
“MPs aren’t just picking a new leader, but picking the nation’s new PM. Penny hopes there will be ample opportunity for such scrutiny later in the contest in a format that allows detailed questions and insights.”