The King and Queen Consort appeared unmoved by more shouts from anti-monarchy protesters clutching banners on their latest royal visit.
His Highness waved to the gathered crowds before going through a gate into Colchester Castle in Essex this afternoon and didn't acknowledge the group, who were stood nearby behind a police presence.
Yellow placards with the words "not my King" were held up as the couple made the entrance as they marked its new city status.
One of the protesters, speaking through a megaphone, said as Charles and Camilla got out of their car: "Answer your critics Charles, come and talk to your critics."
The man then added: "Why are you wasting our money?"
The protestors led by Republic - the UK's biggest group campaigning for the election of the next head of state - wanted to make their feelings known in the run-up to the Coronation.
It comes weeks after 20 protestors from the movement held up huge signs with the message emblazoned across them as the royals arrived in Milton Keynes.
The King appeared in Essex less that two months before his Coronation.
The mega event in London and Windsor in early May has come under fire from protestors who are determined to make their voices heard.
But their calls were almost completely covered by repeated chants of "God save the King" from hundreds outside the venue in Colchester.
The King and his wife, who donned a Fiona Clare couture coat for the occasion, later met school pupils on an educational trip to the castle, which included the viewing of artefacts.
Graham Smith, CEO of Republic, feels it is "absolutely right" to interrupt royal visits.
He says the potential £100million Coronation cost is an "insult" with people struggling to pay their bills.
Citing a recent poll suggesting the support for the monarchy among people aged under 45 has dropped below 50 per cent, he says they will continue until the King meets with them to discuss the concerns.
He told BBC Essex: "We want to point out that this Coronation is a massive waste of money - he doesn't need one, he is already king, why does he feel he can be head of state without a vote being cast?
"We want to raise awareness of the opposition to the monarchy. It is growing, polling is showing a big shift and people are struggling with the cost of living crisis.
"Why doesn't he talk to us, face up to his critics and answers the questions?
"It is absolutely fair - this is for the future of everyone. We have to protest where Charles is going to be."
He added: "We believe the British public should be asked, do you want Charles or a choice?
"The tide is starting to turn against the monarchy and we need a serious debate about its future."
Charles and Camilla's visit to Colchester included a meeting at Castle Park with some of the people involved in the city status procession last year - including charity leaders, volunteers and refugees who have settled in Essex.
