An Insulate Britain protestor who branded her sentencing hearing 'obscene' before she along with eight others were jailed is going on hunger strike.
Husband Andy Smith, 45, says he is "terrified" for partner Emma Smart, but supports her choice.
He said he and his wife, a scientist, discussed her stopping eating if she was jailed by the High Court for breaching an injunction.
Smart, 44, was handed a four-month sentence on Wednesday alongside Ben Buse, 36, Roman Paluch-Machnik, 28, Oliver Rock, 41, Tim Speers, 36, and James Thomas, 47, for taking part in a blockade on the M25 on October 8.
Ana Heyatawin, 58, and Louis McKechnie, 20, were jailed for three months.
Ben Taylor, 37, was given a longer sentence of six months "to deter (him) from committing further breaches" following submissions he made to the court.
Emma Smart told the court she has been working as a volunteer in wildlife conservation and climate activism, and does not have any money.
Addressing National Highways' legal team, she said: "You are claiming more for postage than I have earned in the last three years.
"The fact you are profiting from our stand and trying to save the lives of ... people is obscene.
"Take what I have, come to my house and sell my clothes because that's all I have."
After being sentenced she is now preparing to go on hunger strike from behind bars.
Mr Smith, who volunteers as a climate activist full time but has not taken part in any protests with Insulate Britain, said: "She is incredibly resolute in her actions.
"I stand by her in all the decisions she makes. Morally they are in the right in this instance and she really stands by her convictions.
"She's an incredibly passionate person who has spent her whole entire adult life trying to save wildlife and protect the environment. That's deeply ingrained in who she is.
"That freedom to go out on to the street and protest has been taken away from her, so her going on a hunger strike in prison is another way to continue that process.
"All nine of them in court today were pretty resolute that you can sentence them, but this isn't going to resolve the problem and people will still continue to protest.
"Obviously I'm terrified. It's a horrible thing for her to go through but I stand by her decision to do that."
Mr Smith said he was aware that Smart would be going on a hunger strike if she was put behind bars.
"It's something we discuss quite frequently, the different ways we can make sacrifices to highlight injustices," he said.
"I'm aware that she had previously talked to other people who've already done hunger strikes and been on hunger strikes. She's a scientist, she's done her research."
He added that the sentences were less than the supporters of the group were expecting so they were "relieved", but still felt it was a "complete injustice".
"I completely stand with them on what they've done and how they've acted," he said.
"I would obviously rather the judge side with them but they did break the law and then they were willing to face the consequences of breaking the law."
The climate activist group is demanding that the government insulate millions of homes to tackle planet-heating emissions and move away from polluting industries to avert the worst scenarios of devastation outlined by scientists.
Spokesperson Liam Norton said Insulate Britain was founded by six members of Extinction Rebellion, which has also caused chaos with members gluing themselves to a plane, train and streets to call for faster action to combat climate change.
