This is the intransigence that has got is to the point we are at now ""The UK needs to make a proposal that is inline with EU law"
if it hasn't escaped your attention the UK for better or worse has decided to leave the EU, at the point of leaving it is up to the UK whether it wishes to adhere in future to EU law, the usual way for these things to be decided is for the two sides to sit down and reach a compromise, this is impossible if one side refuses to enter into any meaningful discussion.
If Mexico and Canada told the US can have new NAFTA deal, but only if they ban firearms, that wouldn't fly either.
Any deal has to be in line with EU law, period. There are plenty of options that can be negotiated, but they have to be in line with EU law. Problem is that the UK wants the EU to break its law in order to maintain their red lines, which are not law, but arbitrary lines from a commitee meeting.
The side refusing to have meaningful discussions is the UK. Rge options where laid out before the vote. The rules where voted for by the UK government.
The UK leaving doesn't invalidate the EU body of laws, in their relation with the EU that law can't be violated. Same with the WTO, where the UK wants pretty much the same, and acts rather surprised how many countries day no to their WTO schedule.
You just can't see it can you ? how can you accuse the UK of not being willing to negotiate when you keep stating "any deal has to be in line with EU law" That is "take it or leave it" not negotiation. The intransigence is on the EU side.
The UK is in the way, way, waaaayyyy weaker position in this whole mess.
The EU can allow themselves to take this "take it or leave it stance". Not only because the EU together is larger or economically stronger, but because the UK insists on keeping a lot of EU-benefits, while wanting out at the same time.
There are exactly three scenarios:
1) You are not an EU member and make new deals on everything with the EU (bilateral agreements). The UK missed that ship and it's actually too late to make most contracts.
2) You are not an EU member, but still adhere to ALL EU laws without any exceptions. See Norway or Switzerland. That has a lot advantages, but also the disadvantages of giving up control, because you have no voting rights in the EU.
3) You are an EU member. (Eventually also a Schengen member, but that is optional. Same with getting the EU-currency, the Euro.)
What the UK wants, is all benefits of being in the EU (no. 3), with being not in the EU (no. 1), which would be no. 2, but they want to make choices on what benefits to take up (like free market access without taxes and duties) and on what "burdens" of the EU to carry, because the membership comes with a few perceived(!!!) disadvantages, like free movement of people.
The UK will loose this. Make a choice, door 1, 2 or 3. There is no other option given and possible.