Anti-Brexit campaigners plan to lodge a legal action in a bid to ban the Government from putting its proposed Withdrawal Agreement before Parliament.

Jo Maugham QC said he believes the agreement, due to be debated in a special parliamentary sitting on Saturday, contravenes legislation stating it is "unlawful for Her Majesty's Government to enter into arrangements under which Northern Ireland forms part of a separate customs territory to Great Britain".


Reports suggest a border in the Irish Sea with differing customs arrangements for Northern Ireland than elsewhere in the UK may form part of the Withdrawal Agreement, with negotiations ongoing in Brussels.

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Mr Maugham plans to lodge a petition at Scotland's highest civil court, the Court of Session, on Thursday and expects it to be heard on Friday.

He claimed if the court finds the proposed agreement is unlawful the Government will be obliged to request an extension to Brexit negotiations, under the terms of the Benn Act, which stipulates the Prime Minister must ask the EU for a delay if Parliament does not agree a deal by Saturday.

Mr Maugham tweeted: "I intend to lodge an immediate petition for an injunction in the Court of Session preventing the Government from placing the Withdrawal Agreement before Parliament for approval.

"We expect that petition to be lodged tomorrow and to be heard on Friday.

"We believe the Government's proposed Withdrawal Agreement is contrary to section 55 of the Taxation (Cross-border Trade) Act 2018."

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That part of the act states: "It shall be unlawful for Her Majesty's Government to enter into arrangements under which Northern Ireland forms part of a separate customs territory to Great Britain."

Mr Maugham added: "We do not understand how the Government might have come to negotiate a Withdrawal Agreement in terms that breach amendments tabled by its own European Research Group.

"Unless and until Section 55 is repealed by the UK Parliament it is simply not open, as a matter of law, for the United Kingdom to enter into such an agreement.

"If the proposed Withdrawal Agreement is unlawful, the Government will be obliged to request an extension as mandated by the Benn Act and in accordance with undertakings given to the Court of Session in Vince, Maugham, Cherry v Boris Johnson."