The suspension of British parliament represents to many "an act of executive fiat," house speaker John Bercow said late last night, moments after some MPs pushed each other.
Opposition MPs tried to block Mr Bercow from leaving his chair to proceed with a ceremony that led to prorogation, before the shoving took place.
The opposition members also held signs reading "silenced", yelled "shame on you" at Prime Minister Boris Johnson's ruling Conservatives and refused to leave the House of Commons chambers.
The tense scene came after MPs rejected Mr Johnson's request to try to break the political deadlock on Brexit through an early national election.
With the future of Brexit mired in uncertainty, parliament was suspended until 14 October.
Brexit, the United Kingdom's most significant geopolitical move in decades, remains in question more than three years since the 2016 referendum, with possible outcomes ranging from an exit on 31 October without a withdrawal agreement to smooth the transition, to abandoning the whole idea.