Many in the Jewish community are rightly sceptical about the letter initiated by Labour deputy leader Tom Watson calling for Jeremy Corbyn to remove the whip from the horrendous Chris Williamson.

This letter, on the face of it, seems to be the latest futile attempt by Labour MPs to look like they are challenging the leader over his failure to tackle antisemitism.

Signing it is easy. 

And then, by merely attaching their signatures to the statement, these very same MPs can return to the bigger picture of working to get Mr Corbyn into No 10.

But by initiating this letter, deputy leader Tom Watson has recognised that there is actually a bigger issue at stake than winning an internal argument over disciplinary procedures against an MP who should have been booted out of the party ages ago.

This letter actually forces MPs into making a binary choice.

Quite simply, if Labour MPs cannot bring themselves to sign it then they can no longer claim to support the Jewish community in Britain.

If they do sign it, they are at least taking some sort of stand and challenging their leader who is unable to show moral leadership himself and remove the whip from Mr Williamson.

By Friday lunchtime, what was most surprising about the letter was not the 120-odd names who have signed it - but the missing names of those who hadn’t.

Over the past few years, the likes of Emily Thornberry, Keir Starmer and Barry Gardiner and Angela Rayner have all presented themselves as allies of the Jewish community.

They, along with politicians such as Andrew Gwynn, Sue Hayman and John Healey, are serious omissions from the list of signatories from Labour shadow cabinet.

And what of Shami Chakrabarti, Dawn Butler, Labour's shadow equalities secretary in the shadow cabinet, or shadow chancellor John McDonnell, who has claimed to want to resolve the party's antisemitism crisis?

By the end of today - 24 hours after the letter found its way into the inboxes of every member of the Parliamentary Labour Party - these MPs will have nowhere to hide on this issue.

By failing to sign this letter, these MPs will have made it clear that they either support the decision to allow Mr Williamson back into the party - or that they are so concerned about their careers that they are unable to challenge their leader on the most vital of issues.