Denise Scott, a grandmother on television, and perhaps one in real life, depending on the roaming adventures of her musician son – Ms Scott couldn't be sure – kept the mood momentarily light: "I had to remove facial hair today using Braille ... but, who didn't?"

At one point she thanked the police for their patient attendance before warning them to "watch out"; activist grandmothers were on the verge of going off.

The hilarity subsided when Dr Gwenda Davey told the story of sitting around a kitchen table six months ago with some other women and deciding enough was enough. They were appalled "with what was happening to asylum-seeker children in Australian-run detention centres". They decided that "if we could get a few grandmothers together we could lobby for change".

As she spoke of the Human Rights Commission findings of despair, the stories from whistleblowers themselves made mentally ill from working in detention centres, and the lack of hope among the more than 900 children locked up for hundreds of days at a time, Dr Davey began to cry, imagining her own grandchildren in such circumstances.

There were songs, and rituals of women swapping scarves as an incantatory invitation to grandmothers everywhere to get on board; and there were more speeches.

But really, there wasn't a lot to say. The protest didn't require a lot of words. The message was a simple one.

"It just isn't right," said Jan Govett, who had travelled down by train with two other grandmothers who are involved in raising awareness about refugees in their community.

One of those grandmothers simply said: "It makes me ashamed."