Is Charles set to fly into a new ‘end the monarchy’ row with his visit to Australia? Palace aids are drawing up a plan for the King’s Sydney trip next year

King Charles will face the biggest test of his reign next year when he flies to Australia – where calls for the country to become a republic continue to grow.

The Mail on Sunday can reveal that royal aides are preparing for a visit to Sydney to coincide with his first attendance as head of the Commonwealth at its summit in Samoa.

A senior Australian government minister last night said the visit would lead to a “renewed conversation” about the country having its own head of state.

Charles will be at the Commonwealth Heads of Government Meeting (CHOGM) next October and is predicted to extend the tour to visit Australia, New Zealand and Fiji.

Matt Thistlethwaite, the assistant minister for the republic – an anti-monarchist role created in the Australian Labor Party last year – told the MoS: ‘The king will always be welcome in Australia and greeted with love by the Australian people. become But in contemporary Australia, his visit will spark a renewed conversation about our own head of state who lives with us, represents us and is an Australian.’

The then Prince Charles is greeted by members of the public during a visit to Brisbane on April 4, 2018

Charles chats with an Indigenous elder during a traditional Welcome to the Country ceremony in Gove, Australia on April 9, 2018

Charles has already been criticized for not having made an official visit to any Commonwealth country despite being on the throne for more than a year.

Isaac Jeffrey, leader of the protest group Australian Republic Movement, added: ‘By the time Charles visits, he will have been king of Australia for more than two years. He was hardly in a hurry to visit us and that’s fine – we don’t need him.’

A recent survey found that 78 per cent of 1,500 Australians believe the royal family should foot the bill for a state visit. In 2011 it cost Australian taxpayers $2.6 million (£1.9 million today) to house the Queen and Prince Philip.

Royal aides will keep a close eye on Saturday’s referendum, where Australians will vote on whether to allow an indigenous voice in parliament. If successful, the Labor government, under Prime Minister Anthony Albanese, said it would hold a vote to test its appetite for a republic if elected for a second term in 2025.

A YouGov poll of 1,200 Australians last month found 32 per cent wanted a republic as soon as possible – up 12 percentage points on a similar survey last year.

For his part, Charles is understood to have been left ‘unsettled’ by the delay in receiving an official invitation from the Australian prime minister.

It is understood that should Charles travel to the country – his 17th visit to Australia – anti-monarchists would use it as the launch pad for their bid to oust him as king.

Sources claim opponents will target official engagements to make their case for an Australian to be the country’s first president.

Australian Prime Minister Anthony Albanese (pictured left) and Labor Member for Hawke Sam Rae (pictured right)

They add that there have been ‘conversations on both sides’ and that ‘the King has made it clear that he is keen to meet as many Australians as possible when the opportunity arises’.

Contrasting the MoS, Shadow Defense Secretary Andrew Hastie said: ‘The King will be very welcome on his first visit. There is a renewed enthusiasm for the Crown down-under and a feeling that we are sharing in something special and historic.’

But Prime Minister Albanian is in no hurry to send a formal invitation. One source claimed: ‘It’s fair to say there was some unease about it. As is protocol, the King cannot respond to anything until he receives an official invitation.’

The palace would not discuss details of talks between the king and Mr Albanese for a state visit.

In May, this newspaper revealed Charles’ plans to visit his first Commonwealth country – Kenya – at the end of the month. This is expected to be confirmed by the palace in the coming days.