There was an article in The Guardian last week ago by John Inman (HERE) on the subject of Brexit negotiations being based on hope rather than a plan. It claims senior Treasury officials believe in the end the EU will concede a good deal for us because we import more from them than we export. It's the old Brexiteer argument again but still nonetheless based on nothing more than hope.
On the same day in The Telegraph there is another article by Jeremy Warner (HERE) which essentially says we must have a deal if we don't want to damage the economy. Andrew Rawnsley in The Observer said, when asked why the government had changed tack recently on the transition period, an official told him it was because, "they had looked into the abyss" (HERE). This has the ring of truth to it.
I have never heard anyone outside of the Brexiteers who thinks it is in the EU's interests to give us a good deal. If after we leave, the British economy freed from the shackles of Brussels as the Brexiteers would have it, soars away into hitherto undreamed of levels of growth the EU would be finished, as would the whole idea of a unified Europe. This is not going to happen.
Faced with the "abyss" that both we and the EU know is looming and which would be far worse for us than for them, not least because we are already deeply indebted and with a slowing economy, what incentive is there for the EU to concede the tariff free access outside the single market and customs union, while offering to cooperate with us on Euratom, medicines, patents, defence, aviation and maritime safety and all the other things that we are full members of now?
They might offer something close but the price would be continued following of EU regulations and probably freedom of movement as well as payments of some kind.
