Jeremy Corbyn will face some of his toughest internal challenges yet at this year’s Labour conference; despite his currently unassailable position as Party Leader.

While Corbyn has weathered votes of no confidence, a leadership challenge and constant backroom briefing from his detractors since taking the helm three years ago, the challenges he faces this year are different – more threatening.

While being challenged by the so-called “moderate” (a term I dislike intently) wing of the party, his supporters envelop around him in a protective shield, but this year disagreements are on his own side – and started to spill into the public domain.

This will be a test for Corbyn, he’s never really had to take on his own side before.

The disagreements are over two key issues. The outward facing Brexit, and the inward facing Democracy Review.

Both issues will be key talking points, before and during conference.

The Brexit battle is somewhat easier to pick over, not least because as I was writing this (on Thursday morning) Momentum – the “grassroots” organisation born out of Jeremy Corbyn’s leadership campaign – said they would not block debate of the issue on the conference floor.

To the unseasoned Labour watcher this may seem obvious.

But, in the glow of Corbyn’s better than expected election showing last year, his supporters did indeed stop the issue being debated.

This means the Brexit battle is now over the policy content of the motion and whether or not there is a vote following the debate.

On both issues Corbyn’s supporters are split.

Some of his core team are die hard leavers, but many rank and file supporters – members of Momentum and in the trade unions – want a future relationship with the EU that looks as much like membership as possible.

A significant number want another referendum on whatever deal May strikes with Brussels.

So far, the Shadow Cabinet has strongly held the line that it wants a general election not another referendum.

That strongly held line could be about to rupture depending on what happens at conference.

If there is a vote, it is highly likely that Labour’s policy will be for a referendum on the deal.

But there are very sound high politics reasons why it is against both Labour’s and the Country’s interest to reveal that now, even if that is eventual policy.

For Labour, it would pull attention away from the Tory’s abject failure to negotiate and let them off the hook again.

For the country, it would incentivise the EU to give us a worse deal in the hope of reversing the referendum, which is by no means a given.

A fudge is in Corbyn’s interest too.

In all the time he has been leader, he has never shown an inclination to take on tough arguments on his own side.

If another fudge gets him through, expect him to go for it. A win for Corbyn will be an inconclusive debate with no vote on policy.

But look out for smoke signals from Saturday’s compositing meeting.

The issue of the vote, and the content of the motion will give clues as to who is on the up on Corbyn’s side – and crucially, are the Corbyn supporting trade unions minded to go their own way for the first time since the Corbyn ascendency?

The internal wrangle is over the Democracy Review.

These are proposed changes to the party’s rules on a raft of issues, some minor and some that have already caused public disputes.

Most notably, how a future leader will get nominated and the seeming never-ending discussion over how it is decided whether incumbent MPs can stand again.

The review itself covers a huge number of areas; some of which really are just a tidying up exercise.

But others are significant and have already elicited public criticism from dyed in the wool Corbyn supporters.

It seems that the trade unions have put their foot down and refused to cede more power to ordinary members.

In response some notable Corbyn supporters have condemned the resulting proposals as a betrayal of the aims of the review.

Corbyn himself won’t go near the negotiations on this but expect further debate in the coming hours and days.

There will be votes on these changes at conference and look out for splits between members and unions to give some indicators of the size and importance of any emerging fissures in Corbyn’s support.

None of this, on the Democracy Review or Brexit heralds the end of the Corbyn era, (or even the beginning of the end) but how Corbyn and his team weather internal challenges from his own base could give some indicators as to how long Corbyn’s Labour will last.

Which brings me on to the last thing to look out for.

All leadership is temporary. At some point there will be another leader at the helm Labour. For now who knows when and who knows who. But again there are some signs to look out for.

A successful trip to mumsnet towers or a national tour that brings you in to contact with lots members can both be indications that people are on manoeuvres. As well as McDonnell and Williamson, it’s also worth keeping an eye out for Thornberry, Starmer and Rayner.

There is no anointed successor to Corbyn’s crown and if fissures are starting to open in his own camp, there are opportunities for people to lay the groundwork for whenever the post-Corbyn era begins.