Tonight could see the hard, frankly boring aspect of being mayor of Greater Manchester - the local government bit - heaves back into view, having been eclipsed by the 'king of the north', Westminster-style national campaigning bit for quite some time.

1/

Followers will know that the Greater Manchester Spatial Framework is the bane of my life. It's the bane of everyone in planning's life, of local government reporters and council leaders. But especially of Andy Burnham's.

2/

For the uninitiated, firstly, lucky you. Secondly, the GMSF is a massive high level planning blueprint for the next couple of decades of development here. It maps out what will be built where between now and 2037, including on green belt.

3/

In 2016, Andy Burnham promised to rip up the draft that had already been agreed, effectively, by council leaders prior to the mayoral election. It was a very unpopular draft that was going to see various parts of the green belt developed in the long term.

4/

The 'aim' (NOT a pledge, as the mayor's office never tires of making clear) was 'no net loss' of green belt. Four years, half a dozen delays and multiple rows later, the final draft has cut green belt take significantly, although not to the point of no net loss.

5/

Skip to the end: it has to be signed off by every town hall - ie voted through. And Stockport council is in no overall control.

The Tories on Stockport council are publicly threatening to vote it down.

6/

So the entire thing could effectively collapse tonight, assuming the vote isn't deferred. If that happens, AB will say the Tories have effectively allowed their green belt to be subject to uncontrolled development as a result; that they've lost credibility.

7/

The plan could still go through the other nine, as a nine-authority job. But there's no two ways about it: this would be a significant blow to the premise of GM. The spatial framework was a central win of the 2014 devo deal, at least in the eyes of those who signed it.

8/

But it would also play to a criticism of the mayor that you hear both from the Tories AND Labour people: that he is more interested in the national campaigning platform stuff than he is in the day job. A loss will also, like it or not, be a blow to his authority.

9/

Not that this is prob of huge interest outside GM. But AB is still talked about in some circles as a future leader of Labour; just as we look back to city hall for the PM's previous record, this, now, is what AB is actually in charge of - not what he's opposing.

10/

So the big boring, technical bane of my life does have a lot of political significance, both for GM and for AB. It's why it was the subject of my first ever q to AB in the Lab selection process for mayor. And why (to my great joy ofc) I may watch Stockport council tonight.

ENDS/