The Great Power Grab? Contrary to what its name suggests the main purpose of the repeal bill will not be to repeal EU law.

Instead, it aims to retain most existing EU law in the UK.

This is a necessary step designed to avoid gaps in UK law once Brexit has happened.

Not all EU law can simply be copied and pasted into domestic law, however.

References to the EU and its laws and institutions will need to be removed and replaced with domestic equivalents.

Countless modifications will therefore be necessary.

In addition, the deal on the UK’s withdrawal from the EU will need to be given domestic effect.

Given the technicality of many of these measures, it is in principle appropriate to confer powers on the Government to bring them about.

The bill defines these new powers in vague and uncertain terms, which confirms fears of a Westminster power grab voiced by Nicola Sturgeon with regard to devolution.

Ministers are given powers “to prevent, remedy or mitigate” deficiencies in retained EU legislation “as the minister considers appropriate”.

The bill then cites a number of examples of such deficiencies, but expressly does not limit the minister’s powers to them.

On the one hand this is hardly surprising given the unpredictable nature of the whole Brexit process.

After all, nobody knows what the UK’s relationship with the EU will look like after Brexit and what aspects of EU law may need to be retained, repealed or modified.

On the other hand, the practical reality of the Brexit process, which will happen under enormous time-pressure, will make parliamentary scrutiny difficult.

The bill provides that some Government measures will need to be approved by both houses of parliament.

But the bulk will only be subject to the so-called negative procedure, under which each house has the power to veto a proposed change within a given time-frame.

Many of the changes will need to be made before March 2019 when Brexit is likely to happen.

This means that the Government will be forced to introduce a huge number of measures between the date on which the repeal bill is passed, probably early 2018, and Brexit day.

Proper parliamentary scrutiny will be difficult if not impossible.

The clause providing that the ministers’ powers will end two years after Brexit day is hardly a consolation in this regard.

Not only will many of the changes have to be made by March 2019, but the two-year deadline may lead to another rush to get additional measures through before it expires.