Douglas Ross had initially called on the prime minister to resign, before changing his mind.
Newsnight’s Kirsty Wark responded with an “ooofft”.
Scottish Conservative leader Douglas Ross is first out the gates as he says PM's position is "no longer tenable".
Senior Tories have been added to the MPs being probed by the Parliamentary Commissioner for Standards.
Douglas Ross intervened as Boris Johnson embroiled in 'cash for curtains' scandal over funding of Downing Street revamp.
Douglas Ross says Labour, Tories and Lib Dems should work together "if parliamentary maths" allow after Holyrood election.