Is this really a big deal?
The UK Supreme Court will decide on whether it was lawful to suspend parliament at 0930 GMT on Tuesday (9:30 am London time).
This is a big political story because it would underscore Boris Johnson's contempt for parliament and laws; which is a tough position to take when the foundation of your leadership is a supposed respect for a referendum.
Yet it might not be that big of a deal for markets.
Sure, expect some GBP strength is Boris gets his hand slapped. It will affirm that parliament is in control and can stop a no-deal Brexit but they have pretty much done that already. Sure, there was a tail risk that Johnson could prorogue again and force a no-deal Brexit but what were the odds of that? I'd say they were infinitesimal.
And if Johnson wins? Well that doesn't change anything either. Parliament comes back as scheduled and on we go.
It all still ends in an election and that's the risk event that everything should be priced around. The problem is that it's so uncertain that it's tough to see through it. So we're stuck muddling along trading Brexit headlines that are full of sound and fury but signify nothing.
So what will happen? The questioning from the supreme court justices hinted that that they could find Johnson acted improperly to prorogue parliament but also rule that they don't have the power to order parliament back. That leaves the entire episode as a win for no one.
Maybe there is a bit of GBP selling on the headlines but I don't see it as tradeable.
