The women unfurled the banner over one of Melbourne's busiest motorways about 7.30am on Thursday.

The two women - Katherine Woskett, 25, an arborist, and Hannah Patchett, 22, a professional rope access worker - hung from the Yarra Bend overpass for three hours and refused to speak to police.

They lowered themselves to waiting police on the freeway's median strip, only after officers from the Search and Rescue Squad prepared to abseil from the bridge to arrest the pair about 10.30am.

Their protest is part of nationwide action calling on the federal government to halt the deportation of 267 refugees, including 37 babies, to Nauru.

The women's action was praised on social media by passing motorists, intrigued by the morning spectacle. 

The two protesters also shared photographs of themselves on social media.

#LetThemStay pic.twitter.com/CUk6LhYwbB— Joanne Faulkner (@JoanneFaulkne17) February 10, 2016

On the Eastern Freeway at the Yarra Bend overpass #LetThemStay banner & 2 women hanging next to it. pic.twitter.com/GmrXdr7X5C— Dimity Paul (@DimityPaul) February 10, 2016

UPDATE: 2 women activists suspended off Freeway are still there & refusing to come down. #LetThemStay #CloseTheCamps pic.twitter.com/zswj2xqnYc— WACA (@akaWACA) February 10, 2016

Another banner was strung across Punt Road on Thursday morning.

And another #LetThemStay banner. Sans abseilers. pic.twitter.com/80T4N4mfn9— Shannon Deery (@s_deery) February 10, 2016

Teachers across Melbourne joined the action in recent days, holding protests on school grounds. Up to 6000 people also took to Melbourne's streets at the weekend over the planned deportation.

Meanwhile, Australian Rabbis have backed the bid from Anglican churches to offer the group of asylum seekers sanctuary.

"We stand in solidarity with the Churches across the country that have offered protection and sanctuary for the asylum seekers who face return to Nauru," rabbis from Melbourne, Sydney and Adelaide said in a joint statement.

"The Jewish community knows and understands the refugee narrative too well. For, as Rabbi Jonathan Sacks has said: 'We once stood where they now stand.' We resist letting history repeat itself.

"As Jewish community leaders, we are deeply concerned about the group of 267 vulnerable men, women and children who may be returned to detention on Nauru. We stand proudly in defiance of such treatment."

Nationwide action against the deportation of asylum seekers gained momentum last week after the High Court ruled in favour of the government's offshore processing regime.

The High Court ruling related specifically to the detention of a pregnant Bangladeshi asylum seeker brought to Australia from Nauru for medical treatment.

However, in ruling that the woman's detention was lawful, the High Court validated the detention of the hundreds more asylum seekers also in Australia for treatment.

Among those asylum seekers are five families living in "community detention" in Melbourne, Lucy Honan, of the Refugee Action Collective, said.

Another five families in Brisbane, one in Sydney and one in Adelaide face deportation after the ruling.

There is no legal basis for sanctuary in Australia, which puts any priest, reverend or rabbi who shields asylum seekers at risk of arrest and possible charges.

Legal experts said the image of fugitives seeking sanctuary in churches and abbeys has been popularised in literature and film but it is "more myth than legal reality" in modern times.

But University of Sydney professor Mary Crock, an expert on refugee law, said that, at a political and symbolic level, it was a "really powerful gesture" and she hoped the churches would follow through with their offer.

- with Michaela Whitbourn