Chuka Umunna - never at the top of the Labour leadership's Christmas card list - has landed himself in hot water again.

This morning the Streatham MP became an unhappy poster boy for a practice usually associated with Dickensian villains on the Tory benches: unpaid internships.

Umunna's office, it was revealed this morning, has advertised a year-long unpaid internship among students looking for a year in industry placement at the University of Leeds.

Very sad to see this from @ChukaUmunna The Labour Party is committed to abolishing unpaid internships and this has to start with our own MPs. #PayUpChuka pic.twitter.com/euPIZJS8JE — Young Labour (@YoungLabourUK) May 31, 2018

Predictable controversy ensued. Umunna protests that the parliamentary authorities don't offer additional funds to pay interns, and he does not take unpaid interns other than those on university schemes:

"I strongly believe that interns should be paid and, for that reason, I do not have any unsupported interns working in the office despite the many requests received. For many years, my office has only accepted students undertaking work experience as part of supported university schemes, or short work experience placements from the schools in my constituency.”

Awkwardly, though, Labour's 2017 manifesto called for a ban on unpaid internships.

Umunna might have expected a quiet word from the leadership. Instead, having already been humiliated by activists who started a #PayUpChuka hashtag, a briefing note circulated among the entire PLP this afternoon implicitly rebuked him, pointedly reminding Labour MPs that unpaid interships are against party policy.

Leading with the oh-so-subtle subject line "Intern Reminder", it read:

"This is a reminder to all MPs that it is against Labour Party policy to employ unpaid interns. As part of our 20-point plan for security and equality at work, set out in the 2017 General Election Manifesto, we have pledged to ban unpaid internships."

Poor Chuka. A salutary lesson: for the leader's office, revenge is a dish best served in front of all 256 of your colleagues. And their (paid) staff.