The Green Party's senior politicians are split over whether to back Brexit
Officially the Greens are against triggering Article 50 - the process by which Britain is set to leave the European Union. Green party co-leader Caroline Lucas said on Tuesday that she would not "capitulate" to the Tories and back Brexit.
"I will not be capitulating to the Tories over Brexit - and will vote against prematurely triggering Article 50 in the Spring," she said in a statement.
"As the co-leader of a Party which stands for environmental, social and economic justice I will not support a government offering no assurances to EU nationals living in Britain, threatening to turn this country into a tax haven and planning to throw us off the Brexit cliff edge by ending our membership of the Single Market and Customs Union."
In an interview with BI, Lucas added that the Greens were "very strongly a Remain party" and criticised Labour leader Jeremy Corbyn for failing to show leadership on the issue.
"You know the Greens, we make the joke sometimes that Labour has one leader but many policies, well we have two leaders but one set of policies that people can be confident about," she said.
However, while Lucas will vote against triggering Article 50, her only Green party parliamentary colleague is likely to vote against her own party.
Green peer Baroness Jenny Jones told BI that she "wants [Article 50] triggered" and would be happy to support a simple bill put forward by Theresa May paving the way for Britain to leave the EU.
However, she added that she would not support the bill at any cost and may vote against if it contains a so-called "Henry VIII clause."
Jones' decision to defy the overwhelming anti-Brexit position of her party has previously caused anger within the party.
Last year Jones faced calls from her former Green party colleague on the London Assembly, Darren Johnson, to step down as a Green peer, after she campaigned in favour of Brexit.
In a Facebook post Johnson described Jones' decision to back Brexit as "wickedly irresponsible to the point of evil."
Johnson was among a number of prominent Green party members to sign an open letter calling on Jones to apologise for her role in the Brexit campaign.
"Your actions since the result of the European Referendum, and the anger directed at you from fellow members, leaves us wondering exactly how well you can claim to represent Green Party members in the House of Lords," the letter stated.
"Not only do you no longer represent us, you are now becoming an active and serious liability to the causes that we fight for."
Those close to Jones say she has kept her head down since the row.
"There was an open letter last summer but Jenny answered it and it was amicable," one source said.
"Jenny has done her best to empathise and not wind people up," they added.