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LONDON — The Green Party is unique in British politics in having not one, but two leaders. As well as Brighton MP Caroline Lucas the party is also headed up by Jonathan Bartley.
Bartley is best known for his public confrontation with David Cameron during the general election campaign.
Bartley, who has a disabled son, famously confronted Cameron about the Conservative manifesto pledge to move away from including disabled children in mainstream education.
Bartley describes it as a "pivotal" moment in his life.
"I would always class myself as a floating voter," he tells me.
"I was on a journey and the pivotal moment for me was that confrontation with David Cameron and it was at that point that I took a long hard look at party manifestos and decided that there was only one party that I could really join. The Greens were a natural expression of my values. It felt like coming home."
Green politics was not Bartley's first home however. After leaving university, Bartley spent a brief spell working for the campaign of former Conservative prime minister John Major.
"Back in the early 1990s I finished at the London School of Economics. I'd done a degree in social policy and I wanted to apply it. So I worked in parliament on a cross party basis and the story goes that I was sharing an office with Sir Graham Bright's secretary. Graham Bright was John Major's PPS.
"She said 'do you fancy getting some experience on John Major's campaign team?' And I said 'hell yeah'.
She said 'do you fancy getting some experience on John Major's campaign team?' And I said 'hell yeah'.
However, he denies any long-standing involvement with the party.
"I did that for six weeks so I think it's been rather exaggerated. I was actually making the tea.
"I was not an advisor, I was not a staffer and I am so far from the Conservatives you wouldn't believe."
Bartley is also rare in British politics in being open about his faith. In 2002 he set up the religious think tank Ekklesia, which he continued to run until leaving to become Green Party leader last year.
"My great, great, great, great grandmother was Elizabeth Fry, the Quaker prison reformer," he says explaining his own beliefs."
"So I come from that kind of non-conformist, slightly subversive strand of faith."
Days earlier, Liberal Democrat leader Tim Farron ran into trouble after struggling to answer whether he believes people who have gay sex are committing a sin. Bartley tweeted Farron urging him to "be honest" about his beliefs.
"I tweeted him and said Tim you need to come clean on this," he says.
"I don't think that if you have faith you have to believe that being gay is sinful
"I don't think that if you have faith you have to believe that having gay sex is sinful.
or that having gay sex is sinful. I certainly don't believe that and I know many people of faith who don't believe that.
"I am passionate about equality and I'm proud of our history of pushing for equal marriage and equal rights and that for me is a natural expression of my faith and there are many people of faith who share that perspective.
He says Farron should be forced to explain his position.
"I still don't think that Tim has answered the question. He's said that he doesn't think that being gay is sinful but he hasn't addressed the central issue and he should be pushed on that. I think it's important that people know where we stand. I know where I stand. I'm 100% down the line for equality and I would hope that Tim would be the same."
I ask him why he believes Farron has been slow to clarify his views.
"I guess people have to reach their own conclusions about why he can't give a straight answer to the question," he says.
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Bartley's job-sharing arrangement with Lucas is unusual and I wonder how it works in practice. Does Caroline do Mondays to Wednesdays and then Bartley does the rest of the week?
"No. With my son who is disabled I need time to go to hospital appointments and to see the OT and the physio and to deal with issues around schooling. He's a power wheelchair user, he's got cerebral palsy and he's got learning difficulties, so it's not that I work two days on and two days off. I work all the time but within those days I have to carve out time to go to hospital appointments and last week I did three or four hours with an OT appointment and a wheelchair assessment and next week I will be going to hospital with him for half a day.
"So it's that sort of pattern really. So not some days on and some days off, but just being around doing the job all the time but having chunks of the day available to do those sort of things."
But how does it work when he disagrees with Lucas? Do they need someone else to come in to break the deadlock?
"I don't think we've ever disagreed," he insists
"Can you recall any time?" he asks Lucas, who is sitting beside him on the train back from their campaign launch."
"The one area of disagreement is about wearing a tie," he laughs.
"She's in favour. She wants to wear a tie sometimes and I don't."
She wants to wear a tie sometimes and I don't."
Although he and Lucas may get on well there are little signs of blossoming relationship with their rival parties. Their call earlier this week, for a meeting with the leaders of Labour and the Liberal Democrats to discuss forming an anti-Tory "progressive alliance" was rejected by both parties.
Bartley tells me he was hugely disappointed.
"We've been inundated with emails from people in the last 48 hours since we made that open letter to the other party leaders with people saying please do this, this is really important and really valuing it," he insists.
"There's a lot happening in local seats happening around the country despite what Jeremy and Tim are saying and if Richmond is anything to go by, the local Labour party wanted a vote on whether they should field a candidate and the central party said 'no you have to field a candidate' and not only did Labour lose their deposit but they got fewer votes in Richmond than they have members in Richmond. And that's quite astonishing. so this has a life of its own."
"It's hard to reach any other conclusion than they are putting party interest above national interest. We'd like to change their minds. The door is open but its hard to reach any other conclusions."
With polls suggesting that support for the Greens is hovering between just 2-4% it could be a struggle for them to avoid getting squeezed. I wonder what a successful night would be for them on June 8th.
"The polling average is around 4% as I understand it which is higher than our general election result. Things are so turbulent at the moment and if the last two years have taught us anything it is that things can change very rapidly in a very short space of time and aren't necessarily what you would expect.
"Obviously a successful night would be making gains and increasing the vote share but a really successful night would be progressive parties working together and what is important about the narrative right now is all the questions are about how big Theresa May's majority will be and there is only one thing that will change that and that is progressive parties working together."
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