So let's look at the line-up so far:
Boris Johnson - lied about not knowing about the Downing Street parties and, errr....well, lies in general.
Nadhim Zahawi - says that the PM is telling the truth about not knowing about them - ie. he's a liar too.
Rishi Sunak - ditto, hence a liar.
Matt Hancock - lied to his wife (ex?) about his extra-marital affair.
Owen Paterson - brought Parliament into disrepute by doing paid lobbying work for two companies.
Dominic Cummings - lied about his reasons for going to Barnard Castle during lockdown.
Liam Fox - "The free trade agreement that we will have to do with the European Union should be one of the easiest in human history.” Lies.
David Davis - assured parliament that his department was creating detailed impact assessments of Brexit’s effect on the British economy. He later confessed to a select committee that this was untrue and in fact no impact assessments had been made. Liar.
Jacob Rees-Mogg - conspired with Steve Baker to accuse, from the floor of the commons, the civil service of trying to scupper Brexit. Baker later apologised. Rees-Mogg has never done so. Liar and a nasty piece of work.
And, no doubt, many more if I put my mind to remembering them all.