In a leader from the paper's editorial team, released in advance of Thursday morning's publication, The Sun claimed Kendall, Labour MP for Leicester West, was "about the only prayer [the party] have".
The Sun's managing editor, Stig Abell, posted a picture of the editorial, which decried current front-runner Andy Burnham's performance in Wednesday night's hustings.
The Sun endorses Liz Kendall, in a grudging sort of way. pic.twitter.com/4AM8XoQquS
— Stig Abell (@StigAbell) June 17, 2015
The paper picked up on a slip from Burnham during the hour-long debate, when he said "the party comes first always", rebutted quickly by Kendal who corrected him, saying: "The country comes first."
Didn't learn much from tonight's #labourdebate.
Most revealing moment (Vine thingy courtesy of @journostephen)
— PeterMannionMP (@PeterMannionMP) June 17, 2015
Party members, trade unions and MPs will all vote on which of the four candidates will succeed Ed Miliband in September this year.