I will always remember walking into Labour HQ with Jeremy Corbyn the day he won the leadership in 2015. I’d been with him since the morning making sure he got to the conference hall, from the podium to post-result interviews. Other than a couple of tricky media interviews – and Tom Watson looking grumpy as Jeremy signed the papers making him leader – the day was relatively upbeat wherever we went. After the result at the conference centre we even managed an impromptu rally at a nearby pub.

But the moment we walked into Labour HQ we were greeted like we had turned up at a wake uninvited. I had a few nods from those who remembered me six months previously working there during the general election campaign. There were bottles of wine and some stale crisps left out with a group of the most senior directors gathered around them. It was hardly a welcome party.

The next thing I remember was one of them walking over, pointing to a load of large folders and saying, “see those folders over there? That’s how the Labour Party works, see you Monday.” They then walked off and left before I could say anything. This was day one and, to be honest, there was little change in tone from the directorate level after that.

To give you an insight into how bitter things were to become, when I tried to return to work after we won the 2016 leadership election (I had resigned my post to head up Corbyn’s communications on that campaign) one director tried to delay it. Despite knowing perfectly well that I was a recent father and my young family relied on my income, I was not allowed to rejoin until I went before them for a bizarre unofficial meeting.

I had no choice, so I went along and took a colleague who I worked with to provide support and act as witness. The meeting took place in the general secretary’s office – but he wasn’t present, instead it was two other party directors. I had pages of random news stories and tweets put before me with at best tenuous links to my work. To give you an idea of how tenuous they were: many were old tweets from John McDonnell.

It became a kind of show trial. The party director would put random sheets of paper before me and ask me to denounce them. Or, at least, deny that I agreed with them. It got to the stage that I had to laugh at how ridiculous the process was. At that point, the other director who was there to support her looked awkward and embarrassed, and ended up supporting me.

After the meeting I was readmitted to my previous role as an advisor. But the only reason for this meeting was to intimidate me and send a signal to the leadership. It highlights the level of toxicity at the most senior executive director level.

Another story comes from the early hours of Friday morning after the Brexit referendum result. I was at Labour HQ working on talking points for Labour people who had broadcast commitments the next day. It was a big day, and this kind of work was necessarily collaborative, so I asked a colleague to help me. When he turned up, he was refused entry to the building despite being an advisor for several months.

His entry was refused by a party director on the basis that, in his youth as a student, he had been a member of another party. This was over 10 years ago. The information was public knowledge, he had been asked about it before. The individual in question had even gone on to work for the Treasury after he left university. But Labour’s HQ was now trying to stop him entering the building to do his job after the biggest political event in a generation.

Obviously, I asked why. “It could leak to a newspaper,” I was told. It was 5am and I was having a stand-up argument in Labour HQ in front of the other staff. I pointed out that our country had just voted to leave the European Union and that the political background of an advisor who was consulting on a briefing note would probably not be the biggest story of the day. Also, as no-one else in the room had a background in economics, and this advisor held a PhD, it might make sense to have someone like him to help us prepare our response.

It wasn’t resolved and the argument carried on. I had to take the issue up with the general secretary and threaten to wake up the leader of the Labour Party to get him to come to the building. In the end, they let the advisor in. But this story shows that, in the midst of a national crisis, the factionalism in Southside did not relent one bit. In fact, it intensified.

Sadly, I have plenty more stories where these come from. And it should be remembered that not all people at Labour HQ behaved in this manner, and some junior staffers just did to curry favour with certain directors. I share the stories now to give people – particularly party members – an insight into how bizarre Labour’s HQ was at times. None of this behaviour was necessary. None of it was constructive. It carried on over years and harmed the party enormously. But the past is a land to which none of us can return. What matters now is what comes next.

I voted for and supported Rebecca Long-Bailey in the leadership campaign. But the biggest defeat for the Left earlier this month was not the election of Keir Starmer on a progressive programme. It was the loss in the National Executive Committee (NEC) by-elections to replace those former NEC members who are now MPs. The National Executive Committee is the body that runs the party. Even the leader has to adhere to it.

Unfortunately, there is now a voting bloc of people on the NEC who are opposed to many of the democratic changes, and many of the policy positions, we’ve seen in recent years. These new figures were elected on a slate organised by Labour First and Progress – the right-wing of the party, whose political bedfellows were responsible for many of the worst aspects of the leaked document. They now form a bloc on the NEC which could horse-trade with a new leadership to drive through regressive measures and mute the membership.

Following the by-elections, there is a potential majority of four against the progressive agenda on the NEC. However, that could be reversed this summer. If the Left was to win the NEC elections, it would mean there was an even balance on the NEC between those in favour of membership democracy and any opposing coalition.

In the recent NEC by-elections, the Left slate was split. If there had been a united Left slate it would have won. To be honest, the Left ran poor campaigns, overshadowed by the leadership contest, and we can’t afford to make that mistake again. In my CLP nomination meeting people were asking each other who the NEC candidates even were, let alone what they claimed to stand for.

NEC elections can’t be treated this casually again. They are too important to safeguarding the party against the kind of behaviour we have seen in the leaked report. The NEC must defend members’ interests when they are under attack from an unaccountable elite.

There was a feeling earlier this year that the by-elections weren’t vital because the real elections would happen this summer. However, given the coronavirus, that is no longer a certainty. In fact, if they are delayed until next year to coincide with the already delayed National Policy Forum elections, it could be a year with a sizeable anti-democratic voting bloc on the NEC. That is more than enough time to reverse any of the structural changes that were intended to empower members and challenge the toxic culture revealed in the report.

We need to ensure the NEC elections go ahead this summer. And if they do, there needs to be one united Left slate that ensures those elected have a mandate to defend members’ interests and never again allow the party to descend into the disgraceful mess that the old Southside presided over. The bad old days when a member-led organisation is overruled by an out of date, out of touch and out of control managerial elite cannot be allowed to ever return.