Jane Fonda will spend the night in a police cell on Friday (01.11.19).

The 'Monster-in-Law' star will have to sleep behind bars tonight after she was arrested - the fourth time she's been detained in as many weeks - by U.S. Capitol Police inside the Hart Senate Building for her part in a climate change protest.

Jane was reportedly seen giving a thumbs up as she was led away by police along with actresses Catherine Keener and Rosanna Arquette, who were also arrested, according to gossip website TMZ.com.

The 'Gracie and Frankie' star's arrest comes after she recently said she was planning to relocate to Washington DC, with her main goal being to get arrested.

Jane was inspired by teenage activist Greta Thunberg, who was ''so traumatised'' by the threat of climate change she ''stopped eating and speaking for almost a year''.

When asked what moved her to protest, Jane said: ''I read Naomi Klein's new book. It's called 'On Fire: The (Burning) Case for a Green New Deal'. [One of the things about the book that really changed my life] was the way she wrote about Greta. I mean, I knew about Greta, I didn't know she was on the spectrum. And I didn't really understand what Asperger's meant.

''When Naomi described it, I realised that here is this young person who ... she's not influenced by what other people think. ... On the spectrum, if they are interested in something, they have a laser focus on that and whatever the denials and rationalisations the rest of us indulge in, that doesn't come into play with her.

''And she read the [Intergovernmental Panel on Climate Change] report and she realised that the crisis was barreling straight at us, like a train, and looked around and people weren't behaving appropriately. It so traumatised her that she stopped eating. I hadn't realised that she stopped eating and speaking for almost a year. And that really hit me.''