What would happen if the UK parliament voted to pass the deal, but voted against the political declaration? What on earth would happen then?
That's a 40-billion-pounds question at the moment. We'll see what the EU says if one passes and the other doesn't. Technically if both don't pass, the requirements in the (domestic) UK withdrawal bill aren't met. Or so says the BBC.
Friday's vote will not allow Parliament to ratify the entire withdrawal package, because the law allows this only after the passage of a "meaningful vote" on both parts of the deal.
The prime minister has already lost two such votes on the full deal by large margins, and Commons Speaker John Bercow had ruled out bringing the same motion back a third time without "substantial" changes.
However, the government says a vote on the withdrawal deal alone will be enough to meet the criteria laid down by EU leaders for the postponement of Brexit from 29 March to 22 May.
The Attorney General's view is that it's not a big deal that the declaration isn't being voted on:
Attorney General Geoffrey Cox told MPs the deal must be approved by 23:00 GMT if the UK wants to "secure our legal right" to an extension to Brexit. [...]
He said it did not amount to a "meaningful vote" on the overall deal - as it did not include the political declaration but he said the EU had accepted that that part of the deal was still open to negotiation, while the withdrawal agreement was not.
However his opposition counterpart disagrees:
Shadow Attorney General Nick Thomas-Symonds said passing only part of the deal would not meet the requirements of the UK's EU Withdrawal Act, which requires approval of the political declaration as well.
My guess is that if the Agreement is approved by MPs, the EU will grant the May 22 extension, just so it doesn't look like it caused a no-deal Brexit on a technicality; the blame game is uber important on this. But if the UK still doesn't really/fully ratify by May 22 (according to its domestic law)... then it's going to be a really interesting conundrum.