Thread by @Usherwood

More for me than for you, here's a list of the moving parts in an Art.50 extension request

1/

Either side can request an extension (Art.50(3)), but in practice EU27 have said it has to come from UK

2/

Form of request isn't specified, but would need to be both legally and politically credible

On previous occasions this was a letter from PM to EUCO President

3/

In UK, treaty negotiation is done by government under prerogative powers, i.e. Parliament doesn't do it itself

Hence EU(W)6 Act to require gvt to request an extension

4/

Request for extension =/= extension. Art.50(3) needs unanimity of UK and EU27 to have agreement

Parliament can't require acceptance of request by EU27

5/

Non-compliance by government on requirement would trigger higher-order constitutional problem, since it is bound to follow properly-constituted laws

6/

Appeal to #EUref would not change that, given:

a) Parliamentary sovereignty, and thus
b) referendum as necesarily advisory, and
c) previous extensions have been sought/granted

7/

However, non-compliance mechanisms might take some time, during which time to 31 Oct ticks down

EU cannot unilaterally give more time
Parliament cannot simply take treaty powers back to itself
Art.50 defaults to no-deal on deadline

8/

Put it all together, and you can understand continuing concern in Parliament about start of 5-week prorogation: it can't act on anything during this time

9/

In sum, it will come down to whether anyone's willing to push their constitutional envelope

'push' might be an understatement BTW

/end