Or maybe not that "monumental", because as Reid adds, "the reason we think that tomorrow's vote is less important to the pound than the striking of the deal itself is that all the major UK parties now support either a second referendum which is unlikely to have no deal on the ballot paper (Liberal Democrats, Labour, SNP), or a concrete deal with the EU (Conservatives)."

That said, the market's initial euphoria following the deal headlines which sent cable as high as 1.30 evaporated quickly as the DUP negative stance quickly became apparent and made the parliamentary math for tomorrow's vote a lot more difficult. As Reid explains, "most respected sources I've seen over the last 12 hours suggest Mr Johnson will be 0-20 short with momentum slightly going in his favour as time progresses."

To demonstrate just how confused everyone is over tomorrow's vote outcome, online bookie Ladbrokes is now offering even odds on the vote outcome.