That was the message from Austinmer four-year-old Ellie Yang to Prime Minister Malcolm Turnbull on Monday night, as she gathered with her family and 150 others at North Wollongong beach.

With her mum Jackie Bailey, Ellie was keen to speak up about her feelings on asylum seekers.

“We call her our little poppet, and she has been asking me ‘Why aren’t I in jail if they’re in jail’?” Jackie said, standing with Ellie as she clutched a sign bearing her message.

The family joined the last minute gathering, which was organised on Monday and held to coincide with protests around the country, over the treatment of 267 asylum seekers – and 37 babies – who could be sent back to Nauru after last week’s High Court decision.

Bulli mum Jennifer Macey stood with her kids Esther and Billie holding a placard saying “My family fled war too”, highlighting the similarities between her family’s experiences in Europe during World War II and those of refugees today.

A former Wollongong teacher Pam Joyce spoke passionately in front of the crowd, asking the government to put aside “political purpose” and consider the lives of the seriously ill children facing deportation.

“It is not OK to say we are saving them from drowning and then take their life away anyway,” Ms Joyce said.

The Australia-wide protests come after the High Court last week rejected a legal challenge to the federal government's offshore immigration detention regime.

The court considered the case of a pregnant Bangladeshi asylum seeker who was brought to Australia from Nauru for treatment for serious health complications. She faced the prospect of being returned with her one-year-old child.

In a majority decision the court said the woman's detention on Nauru was not unlawful. It also ruled the commonwealth's role in her detention was authorised under Australian migration laws, and the government's offshore processing deal with Nauru was valid under the constitution.

On Monday, Immigration Department chief Michael Pezzullo told a senate estimates hearing that some of the 267 asylum seekers waiting to be flown back to Nauru are suffering from cancer and terminal illnesses, and the first returns could potentially be made “within days”.