Referendums on scrapping the monarchy should be held every 10 years, the "naughtiest" debate of the Labour Conference heard tonight - while an MP said saying an oath to the King is "ridiculous".
Party members in favour of replacing the Sovereign with an elected head of state said the subject must no longer be a "taboo" - amid questions over whether Charles III will interfere in politics.
But speakers conceded there is a long way to go to persuade the public to ditch the royal family .
Paul Richards, of campaign group Labour for a Republic, told a controversial fringe meeting that he favoured regular votes on keeping the King.
And Richard Burgon, the only MP who turned up at the event, questioned why Labour would consider scrapping the House of Lords, but shy away from discussing the monarchy.
He told the meeting in Liverpool: "It's a really important discussion because when we're talking about the House of Lords, when we're talking about a constitution, written or otherwise, when we're talking about votes for 16 year olds, when we're talking about devolution, then how can we not talk about whether or not the head of state should be elected?"
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All MPs have to take an oath of allegiance to the monarch in order to take their seat in the House of Commons, and this week hundreds lined up to do so to the new King following his mother's death.
But Mr Burgon said: "I think it's really welcome. I do think the oath is Runitarian and ridiculous.
"When I was first elected I prefaced it by saying 'as someone who believes that the head of state should be elected I make the following oath in order to serve my constituents'."
Although fringe events - which will see a large number of discussions on a diverse range of topics - are being held throughout the next few days across the city, the content of the debates are not endorsed by party chiefs.
Labour leader Keir Starmer has spoken on various occasions about his support for the monarchy, and this year's conference - which starts in earnest tomorrow - will open with the national anthem being sung.
Labour for a Republic chairman Nick Wall said he did not object as it is a "historic moment" for the country, but added: "I would expect it to be a one off, I think it's reasonable to do it once, but this is a party for the many, not for the one."
Mr Richards opened his remarks by quipping: "Welcome to the naughtiest fringe meeting," before accusing party bosses of being "scared" about bringing the contentious subject into the open.
He stated: ""Why are we so scared? Why is it so taboo? Of course we should discuss it."
Mr Richards said that public opinion could soon turn if King Charles - who holds weekly meetings with the Prime Minister - is caught interfering.
"One of the things that might happen is that Charles will behave like Charles," he said. "He's spent an entire lifetime as a politician and trying to influence government policy."
He continued: "If he starts behaving badly, and it's going to be hard for him not to because that's who he is, it will be against our constitution. People will think that if people are meddling in our politics, it should be our politicians."
Mr Richards said he would advocate a "referendum every 10 years", saying it would be a measure of the monarchy's popularity as time goes on.
He added: "Then you'd have some accountability."
He told the fringe meeting that the last time there was a discussion about abolishing the monarchy at a Labour conference was back in the 1920s - and it was instantly dismissed.
"There's nothing revolutionary about wanting to be a republic," he said.
Journalist Polly Toynbee, who was among the panelists, said that around 60% of the public are currently pro-monarchy - but this is down considerably from a decade ago, when the figure was around 75%.
"There's nothing unpatriotic about being against the monarchy. Patriotism doesn't belong to the right, we all have our own reasons for loving the country."
Meanwhile Dr Adam Tucker, who teaches law at the University of Liverpool, said there are huge gaps around accountability of monarchs.
He said: "It's impossible to see what happens around the monarch and how the monarch's power is exercised, on the advice of who and how often."
One such area is the convention of King's Consent, which means a monarch is able to veto discussions about matters directly affecting them.
Dr Tucker said this opens the possibility that a government could be "dissuaded by the Palace".
Following the meeting Ken Ritchie, secretary of the Labour for a Republic group, stressed that campaigners are not calling for abolishing the monarchy to be on the next party manifesto - admitting this would be "electoral suicide".
He added: "What we're looking for is recognition that this should be discussed."
