The government has published its legal position on proposed Brexit legislation that will break international law - citing parliamentary sovereignty in domestic law as justification for doing so. The one-page statement has been met with derision.

The UK Internal Market Bill, published on Wednesday, sets out how powers currently held by the EU will be shared out after the Brexit transition period ends. It would allow the UK government to 'dis-apply' measures in the EU Withdrawal Agreement giving EU law supremacy, most controversially in Northern Ireland. As such it would breach international law 'in a very specific and limited' way, Northern Ireland secretary Brandon Lewis told the House of Commons on Tuesday.

The admission prompted widespread outrage, including from the Law Society, which said the rule of law was ‘not negotiable’.

Yesterday afternoon, the government issued a one-page statement setting out its legal position on the bill.

The statement says: ‘The purpose of the bill is to promote the continued functioning of the internal market in the UK after the conclusion of the transition period provided for in the Withdrawal Agreement and the European Union (Withdrawal) Act 2018. The bill also provides for how aspects of the Northern Ireland Protocol to the Withdrawal Agreement apply in the UK’s domestic law. In particular it ensures that the government will be able to deliver its commitments to protect peace in Northern Ireland and the Belfast/Good Friday Agreement, and to strengthen and maintain the UK internal market…

‘It is an established principle of international law that a state is obliged to discharge its treaty obligations in good faith. This is, and will remain, the key principle in informing the UK’s approach to international relations. However, in the difficult and highly exceptional circumstances in which we find ourselves, it is important to remember the fundamental principle of parliamentary sovereignty.

‘Parliament is sovereign as a matter of domestic law and can pass legislation which is in breach of the UK’s treaty obligations. Parliament would not be acting unconstitutionally in enacting such legislation.’

The statement was immediately criticised.

Legal commentator David Allen Green said: ‘This really is first-term, first-year undergraduate tosh from the attorney general.’

Mark Elliott, professor of public law at the University of Cambridge described the statement as ‘utterly risible’. He said: ‘The government’s argument is that parliament’s legal capacity in domestic law to make any law it wants somehow makes it acceptable, as a matter of international law, for the UK to renege on it treaty obligations. But the latter does not follow the former.’