MPs and peers will return to Parliament later after the Supreme Court ruled that its suspension was unlawful.
Boris Johnson is returning early from a UN summit in New York, while Labour cut its conference short in the wake of Tuesday’s unanimous ruling.
The PM, who has faced calls to resign, has said he “profoundly disagreed” with the decision but would respect it.
Commons Speaker John Bercow has said there will be “full scope” for urgent questions and ministerial statements.
On Tuesday, the court ruled it was impossible to conclude there had been any reason – “let alone a good reason” – to advise the Queen to prorogue Parliament for five weeks in the run-up to the Brexit deadline of 31 October.
Mr Johnson, who was attending the UN General Assembly in New York, spoke to the Queen after the ruling, a senior government official said, although no details of the conversation have been revealed.
The prime minister also chaired a 30-minute phone call with his cabinet.
A source told the BBC the Leader of the Commons, Jacob Rees-Mogg, said to cabinet ministers on the call that the action by the court had amounted to a “constitutional coup”.
Speaking after the ruling, Mr Johnson insisted the suspension of Parliament had been necessary in order for him to bring forward a Queen’s Speech on 14 October outlining his government’s policies.
But critics said he was trying to stop MPs scrutinising his Brexit plans and the suspension was far longer than necessary.
Addressing the UN General Assembly, Mr Johnson compared the Brexit impasse to the myth of Prometheus.
Referring to how the Titan’s liver was pecked out by an eagle, he said: “And this went on forever.
“A bit like the experience of Brexit in the UK, if some of our Parliamentarians had their way.”
Earlier, the prime minister said he “refused to be deterred” from getting on with “an exciting and dynamic domestic agenda” and to do that he would need a Queen’s Speech.
The court ruling does not prevent him from proroguing again in order to hold one, as long as it does not stop Parliament from carrying out its duties “without reasonable justification”.
A No 10 source said the Supreme Court had “made a serious mistake in extending its reach to these political matters” and had “made it clear that its reasons [were] connected to the Parliamentary disputes over, and timetable for” Brexit.
But Supreme Court president Lady Hale emphasised in the ruling that the case was “not about when and on what terms” the UK left the EU – it was about the decision to suspend Parliament.
The Supreme Court’s ruling led Labour leader Jeremy Corbyn to bring forward his speech at the party’s conference in Brighton from Wednesday to Tuesday so that he could return to Westminster.
Speaking to a crowd of cheering delegates, Mr Corbyn said: “The government will be held to account for what it has done. Boris Johnson has been found to have misled the country. This unelected prime minister should now resign.”
The calls for Mr Johnson to resign were echoed by Scotland’s First Minister, the SNP’s Nicola Sturgeon, Wales’ First Minister, Labour’s Mark Drakeford, and Sinn Fein’s vice president, Michelle O’Neill.
Downing Street has insisted there is no question of him standing aside.
And Mr Johnson was backed by US President Donald Trump at a joint press conference at the UN summit.
“I’ll tell you, I know him well, he’s not going anywhere,” said Mr Trump, after a US reporter quizzed the prime minister on whether he was going to resign.