Theresa May is not even trying to leave the EU, so Owen Smith has nothing to worry about there.
But John Mann, who is becoming to Frank Field on the Labour Right what Dennis Skinner was to Tony Benn on the Labour Left, openly brands Smith a liar.
That is as fatal to Smith's Leadership ambitions as a denunciation by Skinner would be to those of a left-wing candidate. He stands no chance.
Of course, with her broken window, Angela Eagle is also a liar. But she has not lied to, and then lied about, John Mann.