Ahead of a crunch vote on Monday evening about whether rebel MPs can take control of the Commons order paper to push through a bill to delay Brexit and avoid no deal, Boris Johnson's spokesman condemned the plan as "a blueprint for legislative purgatory".
Opening the debate, Sir Oliver said this week would be the last for Parliament to block a no-deal exit, before it was due to be suspended next week.
The lawmakers behind the case want the court to order that parliament can not be suspended and the judge's decision is expected on Wednesday.
The pound sterling hit multi-year lows against the dollar on Tuesday amid fears of a no-deal Brexit but rebounded after Johnson lost his working parliamentary majority.
Despite a warning that Johnson would seek an election if they tied his hands over Brexit, a bloc of opposition lawmakers and rebels in Johnson's party defied him with what they cast as an effort to stop an economically ruinous no-deal departure.
The judge is expected to announce his ruling on Wednesday.
O'Neill argued that the government was showing "breathtaking contempt" for the U.K.'s constitution and said that Johnson's rule was becoming "increasingly autocratic" as a result of these undemocratic moves.
Jeremy Corbyn, leader of the main opposition Labour Party, said he will not agree to a new election until legislation preventing a "no-deal" exit is in place.
The heightened political tension sent the British pound tumbling on Tuesday to its lowest level against the dollar in nearly three years.
Mr Farage has already signalled that he is ready to put up Brexit Party candidates in all 650 parliamentary constituencies if necessary.
From the start, he faced opposition from his own MPs who fear his threat of leaving the European Union without an agreement with Brussels risks severe economic disruption.
'We will leave on October 31 in all circumstances.
Leaked government assessments have warned that no-deal could lead to food, fuel and medicine shortages, but ministers insist they can prepare for much of this.
However, by Tuesday there was little sign that the rebels were about to back down and they challenged Johnson's claim that talks with the European Union were making progress, adding that they were confident of having the numbers to halt a no-deal Brexit in the Commons.
But critics note that there are no formal negotiations with Brussels, and both sides have stepped up preparations for a disorderly divorce next month.
A spokeswoman for the European Commission said Tuesday that it had yet to see any "concrete proposals" from London on how it wants to change the existing deal.
If the election is called, it would be the UK's third since 2015.
Aidan O'Neill, the legal representative of the MPs who launched the challenge, told the court, according to the BBC, that Johnson was abusing his power in office without any accountability or respect to parliament. However, a number of them, and rebel Tories, have said they would be anxious Johnson could simply change the date to beyond 31 October after the vote.