LONDON, Sept. 17 (Xinhua) -- Britain's highest legal body, the Supreme Court in London, started a three-day hearing on Tuesday to determine whether Prime Minister Boris Johnson's suspension of the House of Commons was lawful.
Eleven judges are hearing the crucial case that could have an impact on the constitution and parliamentary procedure in Britain.
Lady Hale, president of the Supreme Court, described the case as difficult because senior judges in England and Scotland had reached different conclusions.
She also said the case will not decide how and when Britain leaves the European Union (EU).
Johnson faces the prospect of recalling the British Parliament from its enforced five-week shutdown if the case goes against the government.
The legal action was launched after Johnson announced the longest ever prorogation of Parliament in a move condemned by opponents as a deliberate attempt to stifle opposition to his strategy to bring Britain out of the EU on Oct. 31.
Lower-level courts in England, Scotland and Northern Ireland have reached different conclusions, leaving the Supreme Court to give a final ruling.
If the judges say Johnson's action was legal, the British Parliament will reopen on Oct. 14 with a formal State Opening and speech by Queen Elizabeth II.
The case was opened in court by constitutional lawyer Lord Pannick, who represents businesswoman Gina Miller, one of the leading appellants.
Pannick told the judges the prime minister had opted for the suspension of Parliament to limit the opportunity of politicians to frustrate his government's policies.
He also argued that power can only be used for its proper purpose, suggesting that for the government to use prerogative power to evade the scrutiny of Parliament stands the principles of constitutional law on its head.
Pannick said the prorogation meant Parliament could not legislate during that period and could not address questions to government ministers or hold debates.
He said that Johnson would not have gone for such a long suspension if it had not been for his desire to frustrate Parliament, adding that "this was an improper motive."
Pannick told the judges: "No prime minister has abused his power in the manner in which we allege in at least the last 50 years."
Protestors gathered outside the courthouse, many holding banners saying "Reopen Parliament" and "Don't Silence our MPs."
The case is expected to last until Thursday, but the decision of the judges may be delayed.