The attorney general has defended the government’s decision to take the fight over how article 50 is triggered to the highest UK court, assuring MPs that the cost of the appeal will be published ‘in due course’.

Jeremy Wright QC told the House of Commons this morning that the article 50 litigation concerned an ‘important constitutional issue’ which the Supreme Court was right to consider in December last year.

He said: ‘That court considered both the government’s appeal in England and Wales proceedings, and five devolution questions referred by the courts in Northern Ireland after a judgment favourable to the government.

‘The secretary of state for exiting the EU has committed to publishing the total cost figures in due course.’

The appeal - R (on the application of Miller and Dos Santos) v Secretary of State for Exiting the European Union - was heard by 11 Supreme Court justices over four days. The court ruled that parliament must vote on whether the government can start the Brexit process.

Wright was asked by Natalie McGarry, MP for Glasgow East (independent), to attest whether the cost to the public purse to prevent MPs from having a ‘meaningful and democratic’ debate was well spent or a waste of public money.

Wright insisted that it was not a waste of public money to explore an issue of such constitutional significance in the highest court in the land.

He added: ‘If she were right that this were a complete waste of money, then three Supreme Court justices would not have found in favour of the government’s arguments.

‘She will also be aware, and I must gently point this out to her, that some of the money spent by the government was spent in responding to arguments made by the Scottish government which were rejected unanimously by the Supreme Court.’

Wright also agreed with Tom Pursglove, Conservative MP for Corby, that a cost cannot be placed on defending such democratic principles.

The attorney general said: ‘I think there is merit in ensuring that the highest court in the land has the chance to consider what is a very significant set of constitutional questions. They have done that. They have produced their judgment. The government has complied with that judgment. The House of Commons and House of Lords have passed a bill accordingly.’