Caroline Lucas and Jonathan Bartley, an outspoken Christian, are the new leaders of the Green Party.

The pair stood on a joint ticket under the banner of "the power of working together" and won the race to replace Natalie Bennett with 86 per cent of the vote. The announcement at the Green Party conference in Birmingham on Friday sparks a new era for the Green Party as they look to exploit Labour weakness and forge a "progressive alliance" with other parties.

The victory means Bartley and Lucas are the first party political leaders to share the job. Bartley said it demonstrated the importance of how to "strike a healthy balance between work and family and other commitments". He joked the Green Party "stand here more united with two leaders than other parties are with one".

In a joint leadership speech after the announcement, Bartley referenced "radical change" bought about by the first Christian Quakers and promised "a radical redistribution of both wealth and power".

He said: "Modern capitialism has delivered excesses that are not just divisive but morally unacceptable. Only a great realignment can narrow the gap that is harrowing Britain." 

Bartley, the party's work and pensions spokesman, is the co-director of the Christian think tank Ekklesia and former columnist for the Guardian on issues of Christianity and politics. Lucas is a former party leader and party's sole MP - for Brighton Pavilion. 

The two leaders called for alliances with other left-wing parties to defeat the Tories. Although this has been ruled out by Labour leader Jeremy Corbyn, Lucas has said his office are privately open to the idea. 

Bartley and Lucas used their speech to back calls for a second referendum on the UK's membership of the European Union. Lucas described the vote to leave as a "heartbreak" and said it felt like a "death of something that while flawed was still infinitely precious". She said "the people should continue should continue to have our say" and that once the details of Brexit have been laid out a second referendum should be called.

With the Labour party in the midst of a bitter leadership campaign, Bartley and Lucas said the country was "crying out for a real opposition and the Green Party must be it". 

They also made electoral reform a key part of their message as Bartley said the UK had a "completely dsyfunctional electoral system". They called for a proportional representation system, an issue last put to the British people in 2011. It was rejected by 67.9 per cent of voters at that vote but Bartley said the vote to leave the EU was a "howl of rage against exclusion" and came from people "ignored by successive governments in successive generations". He said the UK's first past the post voting system was partially to blame because "outside of a few marginal seats your vote does not count".

He added: "Old tribal loyalties are dying. Voters can no longer be taken for granted. The era of two party politics is over. "It is the voting system that is stuck in the past. So change politics and we change people's lives forever."

The party won 1.1 million votes at the 2015 general election, a 2.8 per cent increase on their vote share in 2010. 

Amelia Womack was elected deputy leader and said she was "truly honoured and thrilled" by the appointment.