Boris Johnson has been accused of silencing MPs to avoid scrutiny over his Brexit plans at the opening of a Supreme Court showdown over the decision to suspend parliament.
Lord Pannick, the lawyer representing activist Gina Miller, said the prime minister wanted to “avoid parliamentary control”.
If he was really shutting the Commons just to follow the rules required for a new session, Lord Pannick said, Mr Johnson would have recommended a “shorter” period than five weeks.
The comments marked the opening of a three-day hearing at Britain’s highest court, as protesters outside called for parliament to be reopened.
Mr Johnson announced in late August that he had asked the Queen to suspend parliament for five weeks until 14 October, when a new session would begin with a Queen’s Speech.
Parliament then shut down last week amid protests by opposition MPs.
Mr Johnson maintains the “prorogation”, or suspension, was necessary to allow him to introduce a new legislative agenda.
Last week, a Scottish court found the suspension “unlawful”. Ms Miller and MP Joanna Cherry QC are among those arguing that ruling should be upheld.
But Mr Johnson’s government is appealing that decision, and trying to argue another English court’s decision last week that it is not a matter for the judicial system to deal with.
The PM told cabinet ministers this morning the legal team was “confident in our arguments”.
The hearing will see a bombshell intervention on Thursday from former Tory prime minister Sir John Major, who will give evidence against Mr Johnson.
Lord Pannick kicked off the case on Tuesday, arguing the “exceptional” length of parliament’s suspension was “strong evidence” the current prime minister wants to “silence” MPs because he sees them as “obstacle to the furtherance of his political aims”.
“Parliament may wish to keep a close eye on planning for a no-deal exit during the five weeks,” he said.
“And in the light of parliamentary scrutiny, parliament may wish urgently to legislate during that period.
“It may wish to impose further obligations on the prime minister in the period leading up to the EU Council meeting on 17-18 October.”
Mr Johnson has insisted the UK will leave the bloc on 31 October even as a law passed by rebel Tories and opposition MPs forces him to ask Brussels to delay Brexit to avoid no-deal if no new agreement is reached by the summit next month.
Lord Pannick quoted from a Sky News interview with the prime minister, where he said: “I am afraid that the more our friends and partners think at the back of their minds that Brexit could be stopped, that the UK could be kept in by parliament, the less likely they are to give us the deal that we need.”
Mr Johnson’s spokesman said on Monday that he had brought to the table a number of areas where workable solutions can be found for a new deal, at a two-hour working lunch in Luxembourg with EU Commission President Jean-Claude Juncker.
But the Commission rebutted that claim in a statement released at the same time, saying “legally operational solutions” to break the deadlock had “not yet been made” by Britain.
The UK government will make its case for suspending parliament being lawful on Wednesday.
It is not clear when the panel of 11 justices will give a ruling.