A second European Union referendum should be held in order to confirm or reject the final Brexit package, the Green Party’s new leader has said.

Caroline Lucas was elected to her post on Friday in a job-share with the party’s former welfare spokesperson Jonathan Bartley.

In her first policy commitment as leader she attacked Theresa May’s claim that “Brexit means Brexit”, arguing that the slogan meant “nothing until we know what the terms of any Brexit deal will be”.

“That’s why our Party says, loudly and proudly, we the people should continue to have our say,” she told delegates at the conference in Birmingham.

“And once the principles of any new deal have been set out, we want them put to a second referendum.” 

Ms Lucas made the comments in her speech to the Green Party's annual conference in Birmingham. 

Labour leadership candidate Owen Smith has also commited to a second referendum; Labour’s Jeremy Corbyn has said the country must accept the result.

Theresa May has said that ‘Brexit means Brexit’ while the Liberal Democrats’ Tim Farron has said his party will stand on a manifesto of keeping Britain in the EU at the next general election.

Ukip have long supported leaving the European Union.

Proponents of a second referendum argue that the nature of Brexit was unclear to voters at the time and that many claims made by the Leave side in the campaign were made on a false basis.

The first referendum took place on 23 June; Leave won an unexpected victory of 53 to 47 per cent after unusually high turnout was registered in the north of England.