The government launched its Great Repeal Bill (GRB), at the same time as Article 50 was invoked, to incorporate all EU legislation into UK law at the exact point when the UK ceases to be a member of the European Union.

Policy-makers and the wider public are being encouraged to view the effect of this new bill Рcurrently in the form of a government White Paper Рas an ambitious but [logically] straightforward administrative and legal step.

The Secretary of State for Exiting the European Union, David Davis, presented the bill as a necessary umbrella Act of Parliament to bring all EU legislation under the control of the United Kingdom legislature, prior to formal exit from the European Union.

A government in power seeking to negotiate a Brexit deal for the UK has little choice but to create some form of comprehensive mechanism for doing this. The GRB is, essentially, a mechanism to buy time for future administrations to unravel the EU laws that currently enjoy legal supremacy over all domestic legislation in the United Kingdom – where there is a conflict or dispute.

The difficulty for the British government, and indeed for any government trying to negotiate a withdrawal from the European Union, is the approach to giving effect to such a bill. Without fully considering both the legislative and political implications of the Great Repeal Bill, and its underlying principles, there is a risk that policy-making could be affected in the years ahead.

From a policy-making perspective, the Great Repeal Bill will require future governments and the UK parliament to consider all EU regulations and directives – the two key legislative instruments of the EU – as they have been transposed into UK law.

At the precise moment the UK leaves the European Union, the full body of EU law in the form of regulations, directives and statutory instruments, become ‘domestic’ law. This is the legal effect of the Great Repeal Bill.

What does this mean for policy-making?

A key argument during the UK referendum in 2016, on future membership of the EU, was the legal supremacy of the United Kingdom parliament.

The issue of ‘taking back control’ was contested throughout the referendum campaign. The British politicians who advocated withdrawal from the European Union argued for the legal supremacy of the UK parliament, by negating the supremacy of EU law over UK law.

The nature of law-making, legal supremacy of parliaments and national courts is complex for member states of the European Union. In particular, the ‘highest court in the land’ for all EU member states is the European Court of Justice in Luxembourg.

The impact of the Great Repeal Bill, if enacted in the British parliament, will be to end the jurisdiction of the European Court of Justice on any aspect of UK law – unless the final Brexit agreement involves single market membership and membership of the customs union.

In wider terms, it would be reasonable for policy-makers to conclude that UK policy-making will be liberated from the constraints and considerations of potential conflicts between UK policy and legislation and EU policy and legislation. Since 1973, the British civil service has developed clear protocols to ensure that new domestic policy, in the early stages of drafting government White Papers, does not conflict with existing EU law.

When the full body of EU law becomes, in its entirety, UK law – the legal effect of the Great Repeal Bill – the challenge for future governments and the British civil service will change.

Policy-making will require future policies, enacted into law, to consider the primacy of existing UK legislation – including the full body of EU law covered by the GRB until the point that the UK leaves the EU – and any conflict that arises between new policies and this body of legislation.

This is not a straightforward process.

Embedded in this body of EU legislation are regulations and directives that cover everything from products and standards for manufacturers, workers rights, environmental standards, quality standards, the regulation of services, consumer protection and a wide range of other areas affecting day to day life in the UK.

Many legal experts, including Professor Catherine Barnard at the University of Cambridge, have argued that the legal status of EU law, adopted into domestic law en-masse via the Great Repeal Bill, is not necessarily law can be treated in the same way as UK law, initiated and enacted through parliament.

In addition to the role of future government and future parliaments in determining which aspects of this body of law will be kept and which laws or their constituent parts will be revoked, the British courts could be required to rule on the exact status and legal effect of the Great Repeal Bill.

The civil service will be tasked with ensuring that no conflicts arise between this ‘new’ body of ‘domestic’ legislation and new policies and legislation being drafted by government departments.

One of the ironies of leaving the European Union is that the British parliament, the civil service and future governments could find themselves spending a large part of their time, sorting through this body of law, created as a result of EU membership. This has the potential to slow the process of policy-making in the future. One of the key arguments put forward in favour of ending EU membership, was the liberation of the British parliament to determine its own laws and the affect this would have on freeing up businesses and wider-society to advance without legal constraint from Brussels.

If the practical affect of the Great Repeal Bill is a focus on sorting through the body of law created by EU membership, perhaps taking years to agree in Parliament and legal challenges in the British courts, the whole policy-making process would be slowed considerably.

At this stage it is too early to conclude that this is the most likely outcome of the Great Repeal Bill. The fact that the new parliament assembled after the UK general election of June 2017, will scrutinize the Great Repeal Bill and its future impact, suggests that there is a danger that this Act of Parliament has the potential to create unintended consequences.