The government is to face a major legal challenge to its Brexit policy next week when ministers will be accused of bypassing democracy if it triggers Article 50 without parliamentary consent.

The Times newspaper has seen a draft legal argument which accuses the government of acting unconstitutionally by over-extending the use of royal prerogative, a power which enables ministers to make decisions without a vote in parliament.

It will be heard by the Lord Chief Justice in the High Court next Thursday, where Attorney-General Jeremy Wright will act as barrister for the government.

EU referendum lies didn't influence outcome - #Brexit minister David Davis https://t.co/lJIRjL42nb — RT UK (@RTUKnews) October 5, 2016

In the legal submission, lead plaintiff Gina Miller accuses the government of “undemocratic” behavior and argues the 2015 European Referendum Act clearly states the result of the Brexit vote was “as a matter of law, advisory.”

“Nowhere in the 2015 act does it specify the consequences that should follow from the referendum result,” the submission adds.

Miller, who manages … and is represented in court by Mishcon de Reya, told the Times: “This is not about trying to delay Brexit; it is about establishing legal certainty about the way the government acts.”

Backtracking IMF admits UK is fastest growing G7 economy DESPITE post-Brexit recession warning https://t.co/dFzqM1XG2Upic.twitter.com/wmESBkXYBU — RT UK (@RTUKnews) October 4, 2016

The government argues its ministers are acting within their constitutional powers.

“The country voted to leave the European Union. There must be no attempts to remain inside the EU. We do not believe this case has legal merit. The result should be respected,” Wright added.

Whatever the outcome of the case, it is likely the Supreme Court will have the final say.

The court has said it will fast-track the case so a decision is made in line with Prime Minister Theresa May’s plan to trigger Article 50 by the end of March next year.