The Green Party’s senior politicians are divided over whether to back Brexit

“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“Not only do you no longer represent us, you are now becoming an active and serious liability to the causes that we fight for.”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.