Tory loudmouth Lee Anderson has come under fire after saying anti-monarchists should leave the UK.
The deputy chairman, an outspoken advocate of free speech, yesterday urged British republicans to "emigrate".
It comes after a heavily-criticised Met Police crackdown saw dozens of protesters arrested on the day of King Charles's coronation.
The force has been accused of stifling the right to protest after several people wearing 'Not My King' t-shirts were seen being taken into custody.
But Mr Anderson - who once told Parliament that freedom of speech is "the most important freedom that we have" - came down heavily on the side of the Met.
Man arrested for murder after woman found dead on New Year's EveHe wrote on Twitter : "Not My King? If you do not wish to live in a country that has a monarchy the solution is not to turn up with your silly boards.
"The solution is to emigrate."
In response Labour MP Justin Madders posted: "If Lee Anderson doesn't want to live in a country with free speech then perhaps he should leave it instead."
The Met has come under fire for its handling of protesters, with shadow minister Jess Phillips saying: "Our nation and our King is not so fragile as to not be able to take harmless protest of a different view."
And Labour MP Sir Chris Bryant said: "Freedom of speech is the silver thread that runs through a parliamentary constitutional monarchy."
Mr Anderson's position on free speech has been somewhat puzzling over the years.
In 2021 he told the Commons: "We fought and won a war to protect our freedoms, and freedom of speech, to my mind, is the most important freedom that we have."
And last year he wrote in a weekly column: "Free speech is a fundamental part of any civilised democracy, and no one should be silenced if they think there are important issues that need to be raised."
Among those arrested was Graham Smith, leader of campaign group Republic. After his release last night, he wrote on Twitter: "Make no mistake.
"There is no longer a right to peaceful protest in the UK. I have been told many times the monarch is there to defend our freedoms. Now our freedoms are under attack in his name."
Rowdy revellers storm fence to break into sold-out New Year's Eve firework eventMetropolitan Police Commander Karen Findlay acknowledged concerns about the arrest of protesters but defended Scotland Yard's actions, saying: "Our duty is to do so in a proportionate manner in line with relevant legislation."
Also arrested on Saturday were members of Just Stop Oil and Labour for a Republic.
The Met said it received information that protesters were "determined to disrupt" the coronation - including defacing public monuments with paint, breaching barriers and disrupting official movements.
But campaigners said the protests were "peaceful", describing the arrests as "a dangerous precedent for us as a democratic nation".
The force confirmed reports from Just Stop Oil that 13 demonstrators were detained on the Mall and six public nuisance arrests on St Martin's Lane following protests from Republic.
Three people were also apprehended in Soho, three at Wellington Arch and five on Whitehall on conspiracy to cause public nuisance, with another in Whitehall arrested for religiously aggravated behaviour likely to cause harassment.
The Met said a further 14 people were detained in east London on suspicion of conspiracy to cause a public nuisance.
Human Rights Watch labelled the arrests "incredibly alarming", adding: "This is something you would expect to see in Moscow, not London."
Amnesty International's chief executive Sacha Deshmukh also raised concerns after police were reportedly given instructions to apprehend people with megaphones.
Separately, Westminster Council cabinet member for communities and public protection Aicha Less said she was "deeply concerned" over reports of arrests of members of its Night Star volunteer team, who assist vulnerable people on the streets late at night.
"We are working with the Metropolitan Police to establish exactly what happened, and in the meantime, we are in touch with our volunteers to ensure they are receiving the support they need," she said.