Photo by Leon Neal/Getty Images Is this it? If Catherine West does not withdraw her threat to trigger a leadership election on Monday then events will gain momentum of their own thanks to the relentless logic of the Labour party rule book. The floor will be thrown open to all comers to put their names forward and seek, like West, the 81 nominations required to proceed to a members’ ballot for the party leadership. It would take a remarkable degree of consensus within this battered and divided Parliamentary Labour Party for no-one to take up the opportunity. Could all 403 Labour MPs (West and her band of 10 or so supporters excepted) really maintain a conspiracy of silence by withholding the necessary 81 nominations and putting forward no other candidates? The most pertinent question at the time of writing is whether West will really follow through with this.…