In 1943, Simone Weil wrote an essay called, in English, On the Abolition of All Political Parties. In it, she asks (and I am using Simon Leys’ 2013 translation), “If I am going to say, in the name of my party, things which I know are the opposite of truth and justice, should I first issue a warning to that effect? If I don’t, I lie.”
She delineates three sorts of lies: lying to the party, lying to the public and lying to oneself, and she concludes that the first is the lesser evil.
Mr Turnbull, as forensically laid out by Don Watson, is guilty of all three of these lies.