This is what happens when John McDonnell attacks you on Twitter

I tweeted how the source told me Mr McDonnell was "deliberately moving away" from Mr Corbyn on policy issues, including Brexit, "because he knows leader's days are numbered".

On Sunday morning, the man himself responded: "You know this isn’t true. Let’s test this invented story. Name your so called “senior Labour source.”

“You won’t and can’t because this is just another farcical attempt to sow division & seek to undermine Labour as we challenge for power. You’ll fail as always.”

What bothers me about his actions is not his claim that what my source had told me wasn’t true. After all, only days earlier, he had himself described Labour’s lack of clarity, under Mr Corbyn, over its policy towards Brexit as a “slow-motion car crash.”

Nor is it the shadow chancellor’s futile request for me to name my source. Even he, with his background steeped in neo-Marxist theory, would recognise that democracy would not function if journalism worked like that.

What I do find alarming is how such a senior Labour figure could write the tweet that he did – knowing full well exactly what sort of crowd that his message would strike a chord with.

If John McDonnell, busy man that he is, does not have the time now to delve through the thousands of tweets I have received as a result of his response to mine, I thought I’d share some examples.

Take this one from a man who previously stood himself as a Labour councillor but resigned after endorsing an antisemitic trope about the Rothschilds.

Or this:

Or this:

I could go on and on, John McDonnell. But I won't.

Only to say, that these are the people you inspire. And for that reason alone, yes, I do want you to fail.