Jeremy Wright, the government's top legal officer, is heading to the Supreme Court where the hearing will decide whether the Prime Minister is entitled to trigger formal divorce proceedings between the UK and the European Union under Article 50.
Court documents from the government say judges shouldn't dismiss the referendum as "merely a 'political event'" and note their decision is not made in a "vacuum".
Wright will outline the arguments on Monday when he appears in court to start the hearing. All sides have submitted written arguments ahead of the case.
Ministers want to trigger Article 50 without approval from parliament as a necessity. But last month, High Court judges backed claimants who argued a vote from MPs and peers is needed before talks can commence.
The case was brought to court by a number of parties, but the lead claimant was fund boss Gina Miller. On the steps of the High Court after the ruling she said: "This result today is about all of us: our United Kingdom and our futures. It is not about how any of us voted – each of us voted to do what we believed was the right thing for our country."
She added that the case "is about process, not politics".
Over the course of four days, 11 Supreme Court judges will listen to the arguments, though no judgement is expected until the New Year. The ruling will be broadcast live.
Theresa May has remained confident of triggering Article 50 by March 2017, though she may be waylaid depending on the judgement.
Part of the government's evidence: