Never or always depending on your meaning
Look, he wants an election but he can't move for one until "no Deal is off the table," If |Labour agreed with the Tory bill yesterday he would have handed Johnson a huge advantage in being able to set the date and scupper taking No Deal out of the equation. Johnson could have set a date after Oct 31st and done nothing meaning we left with No Deal on 31st Oct, then had an election. Agreeing to that would have been insane.