Gina Miller has been aggressively targeted for her anti-Brexit stance.
A prominent Indian-origin campaigner, who had mounted a successful legal challenge to prevent former British premier Theresa May triggering the Brexit without Parliament's approval, has filed an urgent judicial review application over Prime Minister Boris Johnson's decision to suspend Parliament.
Gina Miller branded as cowardly Boris Johnson's announcement that Parliament would be suspended from the week of September 9 until October 14, giving MPs hardly any time to debate Brexit before the October 31 deadline for the UK to leave the 28-member economic bloc.
Her urgent legal challenge came as Wednesday's announcement sparked a major backlash, triggering impromptu protests in London and over a million signing an online petition against the move.
"All right-minded Britons, who believe in the rule of law and the preservation of Britain''s internationally respected and democratic traditions, will share my profound sense of dismay at the cynical and cowardly prorogation of Parliament," Gina Miller said.
"I urge our courts to urgently hear my application for Judicial Review before 9 September 2019 - the earliest date that prorogation of Parliament could come into effect," she said.
The 53-year-old investment fund manager had already issued a legal letter of warning to Boris Johnson in the lead up to the prime ministerial leadership contest last month. She had called him out on his failure at the time to rule out proroguing Parliament in order to meet the October 31 Brexit deadline.
"I have received legal correspondence from the Government Legal Department in the last two weeks stating that the whole issue of prorogation is of no more than 'academic'' interest. It is, sadly, all too clear...that prorogation is a desperate reality, not a mere theoretical nicety," Gina Miller said.
As someone who has been the face of the legal battle over parliamentary supremacy in the aftermath of Britain's vote in favour of leaving the EU in June 2016, she explained that the basis of her latest approach to the courts is that it cannot be legitimate or a proper use of the prerogative power to prorogue Parliament when the intention and effect inherent in doing so is to frustrate Parliament and prevent it from exercising its sovereign right to fulfil its elective role and enact any law it sees fit.
On Wednesday, Boris Johnson said that he plans to have a Queen's Speech - the setting out of the formal parliamentary business by any new government - after the suspension, on October 14, to outline his "very exciting agenda" and insisted he simply did not want to wait until after Brexit "before getting on with our plans to take this country forward".
But the Opposition parties and those campaigning against a feared no-deal Brexit branded his move a blatant attempt at rail-roading Britain's exit from the EU by blocking MPs from tabling motions to prevent a damaging Brexit.
Labour leader Jeremy Corbyn described Boris Johnson's move as "a smash-and-grab on our democracy" in order to force through no-deal by leaving MPs without enough time to pass laws in Parliament. He has pledged to try to stop the suspension.
The leader of the anti-Brexit Liberal Democrats, Jo Swinson, said Boris Johnson was denying people their voice through their representatives in Parliament to force through a no-deal Brexit.
Meanwhile, members of the public gathered near the Houses of Parliament in London on Wednesday carrying anti-Brexit placards and EU flags and chanting "stop the coup". The last-minute demonstration attracted hundreds as they started outside Parliament before spreading towards Downing Street.