Tuesday’s National Assembly for Wales by-election in Alyn and Deeside was in some respects wholly unremarkable. In a safe Labour seat, Labour won. Turnout was low.

Yet in other respects this was one of the most extraordinary by-elections I have ever witnessed. It occurred because of the tragic death of Carl Sargeant, a minister in the Welsh government. Sargeant was found dead by his wife in November, a time when sexual harassment allegations were circulating in both Westminster and the devolved parliaments. Days earlier, Sargeant had been suspended from the Labour party and dismissed from his post because of unspecified allegations.

Sargeant’s family, and many people in the Labour party, have laid at least some of the blame for the tragedy at the door of Carwyn Jones – the First Minister who had sacked Sargeant just days earlier. Former minister Leighton Andrews, who ran Jones’s leadership campaign in 2009, has been prominent among those raising questions about the First Minister’s conduct.

Jones himself has described Sargeant as a friend. He has said he did “everything by the book”, and agreed to launch an independent inquiry.

What was already a very difficult and delicate situation for Carwyn Jones was made even more so when the Alyn and Deeside Labour party chose their candidate for the by-election: Jack Sargeant, son of Carl. Jack has already made it clear that he intends to ensure that full circumstances surrounding his father’s death become known.

With feelings inside the Welsh Labour party running very high, Jones was unable to attend the funeral of his late colleague. He has also been unable to participate in the by-election campaign – something that in any other context would be unbelievable for a politician who has long been Labour’s greatest electoral asset in Wales.

Enquiries into Carl Sargeant’s sacking and death are ongoing. But one thing that has been clear for some weeks is that Jones’s position within his own party has been greatly weakened. At First Minister’s Questions last week, he got into a very acrimonious argument about the Welsh NHS with Plaid Cymru’s Adam Price. The First Minister had been poorly briefed – it soon became clear that some of his criticisms of Price (for not engaging properly with the local health board in his constituency) were ill-founded. But even before this emerged, Jones’s antagonistic behaviour looked uncharacteristic and ill-judged. Perhaps the aim was to unite Labour Assembly Members behind him with a public take-down of the opposition’s strongest performer? If so, it failed abysmally. The Welsh Assembly debating chamber is set out so that AMs all have computer terminals in front of their seats. When matters got heated in the chamber, what was striking was how Labour AMs and ministers failed to back up their leader. All of a sudden, many of them seemed to have very urgent emails to attend to.

Jack Sargeant’s by-election victory means that Jones’s problems are most definitely not going away. Indeed, there will be a direct reminder of them in front of the First Minister and everyone else every day. Prior to November, Carwyn Jones had enjoyed a very successful 2017. With Labour apparently facing a difficult general election, and possibly even an historic defeat, he had been front and centre of the party’s campaign in Wales. When Labour emerged triumphant – actually gaining three seats in Wales, rather than losing some, the First Minister understandably gained huge political kudos. His standing within his party had never been higher – there was no longer any doubt, and there sometimes had been in the past, who led the Welsh Labour party.

Now, even if he emerges exonerated from the enquiries, the only question that seems to animate political discussion in Cardiff Bay is when, and not if, he will go.