While some of Australia's biggest stars sipped champagne, protesters had a distressing message.

Protesters have blocked a passenger train line and scaled a crane near Flemington Racecourse on Melbourne Cup day, calling for Manus Island refugees to be brought to Australia.

A car has been driven across tracks at Ascot Vale with a protester locked inside and Metro Trains has told passengers to expect delays of more than an hour.

“We are really appalled at the situation on Manus Island and we think it’s really inappropriate for people to be celebrating when there are individuals with no water and no security,” protester Sonia Arquette told AAP on Tuesday.

The group is not aligned with any organisation.

“We don’t want to be doing this but we feel we have no choice when there are 600 people starving,” Ms Arquette said.

Passive protests have proven ineffective and protesters wanted to make sure people paid attention, she added.

“This should be a priority and it’s not right to be celebrating when this is happening,” Ms Arquette said.

In a separate event, two women have climbed a crane near the racecourse to unfurl a banner which read "SOS: Evacuate Manus Now".

"We are joining with others across Australia to demand that the government evacuate the men on Manus immediately and bring them to safety for processing," Whistleblowers, Activists and Citizens Alliance spokeswoman Charlotte Lynch said.

"This is an emergency. This is an humanitarian crisis. We refuse to sit by whilst the Government, with the complicity of the Labor Party, puts over 600 men’s lives at risk."

The groups are not believed to be affiliated.