The challenge facing Parliament is the conjunction of the Bill’s wide delegated powers, including Henry VIII powers, with inadequate scrutiny procedures for the ways these powers might be exercised.

This combination will inhibit MPs' ability to hold the government to account and neuter their capacity to influence some of the policy choices arising from the UK’s withdrawal from the EU.

Delegated powers are powers that Parliament gives to ministers in Acts of Parliament to make law (in the form of delegated legislation or Statutory Instruments (SI)) without having to pass another Act. An SI is the 'child' of the power in the 'parent' Act and can be used to fill out, update, or even amend primary legislation. Delegated powers to amend or repeal primary legislation are known as Henry VIII powers.

In legislating for Brexit, the government faces a genuine challenge, owing to the tight deadline, the volume of legislation involved, and the need for speed and flexibility to cope with the outcome of the UK-EU negotiations. The use of delegated legislation, including the use of Henry VIII powers, is unavoidable.

But, as the EU (Withdrawal) Bill is drafted, the broad scope of its delegated powers, the inadequate constraints placed on them, and shortcomings in the proposed parliamentary control of the delegated legislation that will be made using them, constitute a toxic mix, for Parliament and the balance of power between executive and legislature. The balance must be redressed in Parliament’s favour by improving parliamentary scrutiny of both delegated powers and delegated legislation.

In a new report, 'Taking Back Control for Brexit and Beyond: Delegated Legislation, Parliamentary Scrutiny and the EU (Withdrawal) Bill', the Hansard Society proposes a three-part solution to the problem:

Previous legislation, such as the Legislative and Regulatory Reform Act 2006, provides examples of ways in which Parliament could introduce safeguards into the EU (Withdrawal) Bill to tighten the scope and application of the powers.

In previous bills which included powers of similar breadth and scope to those in the EU (Withdrawal) Bill, Parliament (particularly the House of Lords) has made the exercise of those powers subject to a strengthened scrutiny procedure (i.e. not the normal negative or affirmative procedure). The EU (Withdrawal) Bill proposes no such procedure.

However, the House of Lords is likely to insist on the use of strengthened scrutiny for the widest powers in the Bill, if MPs do not do so first.

For reasons the report sets out, none of the existing strengthened scrutiny procedures will meet the Brexit need for legislative speed and flexibility, if the government is to deliver a functioning statute book the day after we leave the EU.

The Hansard Society has therefore designed a new strengthened scrutiny procedure - the EU (Withdrawal) Order procedure - for use in this and other Brexit bills. The key feature of the procedure is that Parliament, not the government, will decide how the exercise of the broadest powers in the Bill will be scrutinised.

Concerns over parliamentary scrutiny of delegated legislation under the EU (Withdrawal) Bill arise partly because the way in which Parliament, particularly the House of Commons, deals with delegated legislation is wholly inadequate, and has long and widely been recognised as such. The Hansard Society concluded in 2014 that the system was unfit for purpose and in need of wholesale reform, after it undertook the first in-depth study of the subject in over 80 years.

But successive governments have made no effort seriously to engage with the problem, and the House of Commons, unlike the House of Lords, has not fundamentally altered its handling of delegated legislation in years.

The Hansard Society proposes that a new Delegated Legislation Scrutiny Committee should be established in the House of Commons for the scrutiny of all delegated legislation, including that made under the EU (Withdrawal) Bill and other Brexit bills.