17/10/2017 04:34 BST | Updated 18/10/2017 04:15 BST

The News That Is Making Theresa May Panic About Brexit

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Theresa May's and David Davies's hasty excursion to Brussels comes as the Office of National Statistics issues revisions to the "Blue Book" of national accounts showing the UK is worth £490billion less than previously thought.

Just two weeks after Boris Johnson boasted at Tory Conference that we would need to build another Channel Tunnel because trade will be so great after Brexit, it sounds instead like it might do better as a quick exit for the money and businesses leaving our shores.

The fall in estimated net wealth is so great it means Britain has again become a net debtor nation and has destroyed the claims of ministers, such as Liam Fox, that "despite Brexit" foreign investment into the UK is soaring.

In fact there was a net disinvestment from Britain in the first half of 2017, though it is not clear if that was overseas owners selling up and getting out, or British-based investors looking for a post-Brexit investment haven overseas.

In the circumstances it should be little wonder that Mrs May and Mr Davies have pitched up in Brussels with what appears to be a stash of new offers aimed at to enticing the European Commission into recommending to heads of government that Britain's exit negotiations should move on to including future trade deals. Without trade there is no hope of reversing the decline.

October is traditionally the month of reassessment. Everyone is back from their holidays, and Christmas is still a long way off. The days are shortening and the nights getting colder. Time to shed illusions and dig in for the winter ahead.

And this month the signs are that businesses, previously reluctant to show their hand, are indeed planning for the consequences of Brexit. The nuclear industry - where Britain was once the undisputed world leader in civil power generation and then reprocessing - is on the move, relocating key assets out of the UK, Vauxhall's new owners have postponed any new investment at Ellesmere Port pending clarity on Britain's future relationship with the EU and even the supermarkets, the companies most exposed to any consumer backlash against political positioning, are sounding more and more alarmed.

It may be that Mrs May, if she survives that long, will be able to get to the proposed exit date of March 2019 with some sort of transitional trade deal in place. But at very best this is bound to be a second class version of what we have at present.

Even the so-called "Norway option" would be potentially disastrous for Britain, especially if was accompanied - as is the case with Norway - with leaving the customs union. For a start it would necessitate a hard economic border between Northern Ireland and the Republic of Ireland, firmer even than that between Norwegians and the Swedes who allow each other's customs police to patrol inside the other country: something unimaginable on either side of Ireland's border.

Farmers too, could be immediate victims of any "Norway model" as they would be automatically excluded from the Common Agricultural Policy and the access to European markets it offers.

And let's not forget, the Norwegian model is absolutely the very best that would be available to business by way of any post-Brexit trade arrangement and the government is not even offering that as it has ruled out any prospect of staying in the single market. The reality is that any deal that will be reached will almost certainly be far worse.

That is why it is essential that Parliament keeps and defends its right to have the final say on any and every agreement the government signs up to. Not least because every voter needs to know where their MP stands on such a fundamental decision.

The leave campaign and its ministerial supporters promised us that Brexit would not leave us worse off. When the cards are all on the table our elected representatives need to be free to make the judgement about whether that promise has been kept, and vote accordingly.

Anything less would be an insult to democracy.

Eloise Todd is CEO of Best for Britain, a political campaign fighting to keep the door open to EU membership