Court battle over Brexit could cause 'constitutional crisis,' Iain Duncan Smith warns

Former Work and Pensions Secretary advises Parliament to ignore Supreme Court

'It is not their job to tell Parliament… how they go about their business' (Getty)

The Government's battle with the Supreme Court over Brexit could cause a "constitutional crisis," the former Work and Pensions Secretary has warned.

Iain Duncan Smith suggested Parliament should ignore the Supreme Court ruling on whether or not it can use its executive powers to trigger Article 50.

"What the judges will decide on at the Supreme Court is whether or not the Government can use its executive powers to trigger Article 50," Mr Duncan Smith told Sky News.

"It is not their job to tell Parliament… how they go about their business.

"That's for Parliament to decide. I would simply advise that the Government should ignore it."

A Supreme Court judge has said the EU referendum was not legally binding, ahead of the court case due to begin on 5 December.

Last month, the High Court ruled against the Government and pronounced parliament must be consulted before Article 50 can be triggered.

Lady Brenda Hale has also suggested "comprehensive" legislation may be required to trigger Article 50, potentially delaying Brexit for two years.

Lady Hale argued a replacement of the 1972 Act that brought Britain into the EU in the first place may be needed.

Mr Duncan Smith reacted to Lady Hale's suggestion by saying the Supreme Court Deputy President had "always been opposed to Britain leaving the EU".

She is one of 11 justices in the Supreme Court who will consider whether the High Court was right to rule the Government must get parliamentary approval before triggering Article 50.

A Supreme Court spokesman said: “Lady Hale was simply presenting the arguments from both sides of the Article 50 appeal in an impartial way for an audience of law students, as part of a wider lecture on constitutional law.

“One of the questions raised in these proceedings is what form of legislation would be necessary for Parliament to be able to lawfully trigger Article 50, if the government loses its appeal.

"A number of politicians have raised the same question. Though it was not dealt with explicitly in the High Court judgment, it is not a new issue. In no way was Lady Hale offering a view on what the likely outcome might be.”