Two Labour MPs on primetime TV. Two prominent politicians ruling themselves out of a Labour leadership contest. But that was as far as the similarity went.

Hilary Benn was speaking hours after he resigned - or was sacked - from the Shadow Cabinet. He described Jeremy Corbyn as a "good and decent man" but not a leader.

Framing his overnight removal as a matter of conscience, Benn told the BBC's Andrew Marr: "I no longer have confidence in him [Corbyn] and I think the right thing to do would be for him to take that decision."

In Benn's view, diehard leftie pin ups do not go down well in the real world, or on the ballot papers of middle England.

But while Benn may be drawing on a New Labour truism, this in turn rests on the assumption that voters matter more than the party members when it comes to winning elections.

That assumption was contested moments later by Shadow Chancellor John McDonnell.

Dismissive of the personal appeal of Shadow Cabinet ministers - "we can replace them" - McDonnell's message was that Labour under Corbyn had rejuvenated its electoral machine.

Pointing to success in by-elections and the London mayoral election, McDonnell warned would-be rebels: "Who is sovereign in our party? The people who are soverign are the party members.

"I'm saying respect the party members. And in that way we can hold together and win the next election."

Indeed, nearly a year on from Corbyn's surprise election to the Labour leadership, it is worth remembering he captured nearly 60% of the 400,000 votes cast. Momentum, the grassroots organisation formed in the wake of his success, now has more than 50 branches around the country.

Come the next election, it will be these grassroots members who will knock on doors, hand out leaflets and perhaps even threaten to deselect MPs.

The question for wavering Labour MPs will be whether what they trust more - their own connection with voters, or this potentially unbiddable party machine.