It will be one of the most significant votes
that parliament has held for many years.
Theresa May is on a mission.
Now that her Brexit deal has been signed off in Brussels,
she is determined to get it through parliament.
But to have any hope of convincing the sceptics
on both sides of the debate she knows she must first win over
the people of Britain and their employers.
On it will depend whether we move forward together
into a brighter future or open the door to yet more division
and uncertainty.
No employers are more important than those
in the City of London.
It accounts for up to 20 per cent of the economy
and in the last financial year generated £72bn of tax.
An outcome on Brexit that is bad for the City
will be bad for Britain.
The City of London is Europe's gateway to global capital.
It's going to remain a great global financial centre
whatever happens through Brexit.
I'm not saying that we won't lose some business
as a result of Brexit.
Of course we will.
We'll lose some business and some jobs as a result.
Many City financiers still bemoan the impending end
of the UK's membership of the single market
and its system of being able to sell products and services
from London to clients across the EU
under so-called passporting rules.
Well, we still think that the mutual recognition approach
would have been the best, but that's water under the bridge
because that's plainly not going to happen.
For Catherine McGuinness, policy chief
at the City of London Corporation,
it still clearly rankles that the government
has been arguing in Brussels for a thin financial services
deal based on maintaining parallel regulations,
a so-called equivalence model, rather than mutual recognition,
a more bespoke and ambitious concept that many financiers
had lobbied for.
There's a lot wrong with the current equivalence model.
It's intensely political.
It's not permanent, and decisions
can be withdrawn on as little as 30 days' notice.
And it only covers about a third of the sector.
But we've got to start from somewhere.
There's an indication in what we've
seen of the future framework of an intention
to build on supervisory co-operation,
regulatory co-operation.
We've got to build.
For optimists, the most important part of the deal
is the 21-month transition period
that will follow Brexit in March 2019
because that will allow the skeletal principles
of a future relationship in financial services
to be built out into an enhanced equivalence arrangement,
as they put it.
As it stands, the UK is leaving the single market.
So the challenge now is how we move on
to creating this new equivalence regime.
I absolutely accept there are about half of this...
about half a page of this in the political declaration,
but that covers the whole economic relationship.
And the critical point is, it's in there,
and so we can build on it.
There is a hook for the negotiations.
It talks about autonomy.
It talks about a close, structured, regulatory
relationship between the UK and the EU.
And there are, of course, going to be negotiations around that.
But the point is that we're moving,
I think, in the same direction, and that
is about making sure that there's
the best possible - within the permutations
and the limitations that we have -
the best possible economic relationship
on financial and related professional services.
Thin as the financial services model might look for now,
most in the City feel that it's time to rally behind the deal
that Mrs May has struck.
I think that finance has shown that it can adjust and build
in significant change into its plans and future strategy.
The snag, though, is that parliament is rather less
enthusiastic than the City.
And that prospect has convinced many former Remain campaigners,
and even some hardline Brexiters,
that the right thing to do is to ask the country to vote again.
If parliament is unable to support the current deal,
then I do think there is a case for a second vote,
but only if parliament is unable to support the current deal
because I think in those circumstances
we're faced with a very stark choice, which
is moving towards an exit of the EU without a deal.
And I think that is a calamity, and I think that is a disaster.
And that is something for which we are not ready
and for which plans have not been properly made.
If we follow the path to a no-deal,
financiers aren't really talking of Armageddon.
They do stress there are some key outstanding issues relating
to data access and the continuity
of certain derivatives and insurance contracts.
But banks, asset managers, and insurance companies
have detailed contingency plans in place
to cope with a cliff edge.
One thing is for sure, though: the economic disruption
of a no-deal Brexit will be significant.
More jobs and activities will move to Frankfurt, Paris,
and Dublin, and the tax take from the City in 2019 will not
be £72bn.