The committee said this measure is inappropriate and it is unconvinced by the UK government’s rationale for introducing such constitutionally significant powers.

Currently, section 6(1) of the European Union (Withdrawal) Act 2018 provides that after “exit day”, UK courts and tribunals cease to be bound by the jurisdiction of the CJEU and that retained EU law is to be interpreted in line with any retained EU case law—namely those interpretations of the CJEU which were applicable on or before exit day.

The new powers under clause 26(1) of this bill will empower ministers to require courts to depart from such considerations and instead apply ministerial guidelines that set the tests and considerations as to when retained EU law can be re-interpreted.

There is no indication in clause 26 or the explanatory notes as to what the content of such guidelines might be.

The committee said it is inappropriate for courts other than the Supreme Court and the High Court of Justiciary to have the power to depart from the interpretations of EU case law; that the proposed consultation with senior members of the judiciary on the applicable tests for departures is not an adequate substitute for the determination of such issues in adversarial proceedings in open court – open to interventions and with the assistance of counsel – and that there is no case for such broad and constitutionally significant regulation-making powers, the effect of which may undermine legal certainty.

In its report which scrutinises the European Union (Withdrawal Agreement) Bill, the committee has raised further issues on the bill, including:

• Devolution – the committee recommends that the government, before report stage, sets out what its process for consultation and engagement with the devolved authorities will be in respect of the future relationship with the EU.
• Role for Parliament  – the bill no longer includes a clause that featured in its previous iteration which provided for parliamentary oversight of the negotiations for a future relationship between the UK and the EU. The bill only provides for Parliament to be notified in the event that certain dispute mechanisms under the Withdrawal Agreement are invoked, which is only limited involvement.
• Delegated powers – the bill includes significant delegated powers, including Henry VIII powers. The Delegated Powers and Regulatory Reform Committee has recommended that a sifting process, similar to that in the European Union (Withdrawal Act) 2018, be instituted to scrutinise them. The Constitution Committee agrees that a sifting mechanism is necessary.

Baroness Taylor, chair of the committee, said: “The government should reconsider the implications of clause 26 and the potential for significant legal uncertainty if lower courts are to be given the power to depart from previous CJEU caselaw and previous domestic interpretations of retained EU law.

“The government should also provide for a sifting process for the scrutiny of instruments made under the bill, as recommended by the Delegated Powers and Regulatory Reform Committee.”

Read the full report on the committee’s webpage