From the small office of the Parliamentary Under-Secretary of State, Robin Walker MP you can see what survives of the remains of Henry VIII’s rambling Whitehall Palace. They date from about 1530, and reveal the satisfying pink Tudor brickwork and arched window surrounds of a group of buildings originally devoted mainly to games and amusements. Today Ministers and officials are intensely engaged in more serious preoccupations of state as the formal notification of the UK’s intention to withdraw from the EU is imminent.

DExEU was created from scratch in July last year to oversee the government’s negotiations to leave the EU and establish the future relationship between the UK and the EU. It is taking the lead in government and coordinating all the work across Whitehall that is needed to smooth the transition away from 40 years’ membership of the EU on the best possible terms. David Davis MP and his three other ministerial colleagues will support the Prime Minister (who chairs the EU Exit and Trade Committee of Cabinet) in conducting the negotiations with the EU, including supporting bilateral discussions on EU exit with other European countries.

Whitehall departments will need to have their negotiating plans (schedules of requests and offers) approved by DExEU before they become part of the government’s overall negotiating strategy. Plans by the Lord Chancellor, for example, to safeguard arrangements in the UK for the recognition and enforcement of judgments post-Brexit will need to be proposed to DExEU before being approved by Cabinet as part of the bigger package.

DExEU is at the heart of a new web of government relationships which has resulted in a realignment of roles and responsibilities at the heart of the government machine, particularly between the Foreign Office, Treasury and the new Department for International Trade. Its location in Downing Street is not a coincidence.

Brexit continues to dominate life at Westminster and Whitehall but many of the government’s supporters wonder whether the domestic agenda is being effectively sidelined. The NHS appears to be in meltdown. The funding and delivery of social care look increasingly inadequate to meet the challenges of an ageing population and prisons seem to be a dangerous tinderbox despite the commitment to provide more prison officers. But Labour remains in desperate disarray, in need of reconnecting the metropolitan Left with its traditional areas of support in the north around a new set narratives that could begin to start a return journey to office at Westminster.

At the time of writing this column, Parliament is on a half-term break and the government’s European Union (Notification of Withdrawal) Bill, having completed all its stages on the floor of the House of Commons as befits a Bill of major constitutional importance, awaits its consideration by the Upper House.

Introduced to the Commons just two days after the Supreme Court’s judgment in the Miller case, the Bill was the government’s response to the court’s ruling, by a majority, that it would not be legal for the government to use prerogative powers to issue the Art 50 notice. A resolution of the House of Commons alone, without legislation, would not have been sufficient.

The legislation is undeniably of momentous significance, setting in train enormous constitutional, legal, political, social and economic changes.

Once notification is given, para 3 of Art 50 provides that the EU Treaties will cease to apply on either the date of entry into force of a withdrawal agreement or two years after the withdrawal is given, unless all member states agree to extend the two-year period.

If notification cannot be revoked, giving notification will automatically result in the UK leaving the EU after two years, irrespective of whether an agreement is reached on the terms for doing so, unless other member states agree to extend the negotiating period.

The Bill, a short, tightly drawn measure running to all of two clauses, was fast-tracked through Parliament, and gave parliamentarians their first opportunity to give legal effect to the result of last June’s referendum.

But amendments that might have caused the government problems fell by the way in the Commons. Having pledged last December to endorse the trigger in return for the Prime Minister’s Lancaster House speech in January and with a white paper (rushed out last month in response to MPs’ demands), MPs could hardly go back on a deal they had described as a victory. The government’s thumping majority of 372 at the end of the day in the Commons left the measure intact and unscathed.

It might be thought that if Parliament was serious about asserting its rights it should have the final say on the eventual Brexit deal. Ministers said that Parliament would be consulted. But this was no more than a restatement of the Prime Minister’s Lancaster House undertaking to put ‘the final deal that is agreed between the UK and the EU to a vote in both Houses of Parliament, before it comes into force’.

The consultation would only be on a ‘take it or leave it’ basis. There would be no question of negotiations being re-opened if Parliament refused to endorse what was on the table. If Parliament rejected the withdrawal agreement the UK would simply leave the EU and fall back on the World Trade Organisation.

The outcome is all the more remarkable since the Commons vote was not remotely representative of the votes cast in the referendum. If the 52/48 referendum result had been replicated in Parliament, the government’s majority would have been 26; and three-quarters of MPs did not want to leave the EU in the first place.

In the meantime parliamentary involvement in other aspects of Brexit continues. A large number of reports on Brexit have been published by parliamentary committees in both Houses and more inquiries are continuing. The Commons Justice Committee, for example, expects by mid-March to publish its report on the implications of Brexit on the justice system, an inquiry to which, amongst others, the Bar Council and others from the Bar contributed written as well as oral evidence.

The legislation triggering notification does not, of course, amend any EU-related UK legislation. But it does start a process that will require the UK to enact much more legislation when EU Treaties no longer apply to the UK. The Prime Minister plans to include in The Queen’s Speech in May a ‘Great Repeal Bill’ to repeal the European Communities Act 1972 and transpose EU law (the acquis) into domestic law. These would take effect on ‘Brexit Day’, the day when the UK officially leaves the EU.

In evidence to the Commons Exiting the EU Committee, David Davis MP explained that the Great Repeal Bill would convert the acquis ‘pretty much – not quite – untouched’ into British law. The implication of this statement was that the Great Repeal Bill would only be the start of the process, with consequential legislation, both primary and secondary, to follow before the conclusion of the negotiation (or ratification of the negotiation).

At this stage the government’s strategic priorities in relation to Brexit for the next two years continue to be expressed in fairly general terms. The legal profession can take some comfort from the fact that the white paper acknowledged the underpinning economic significance of legal services to the UK, especially to financial services, and the need for an effective system of civil judicial cooperation, as well as the freest possible trade in services between the EU and the UK. The profession will need to make sure that these messages, informed by the real-world experience of practitioners, are heard clearly and regularly, and understood in Whitehall and at Westminster.