Natalie Bennett has insisted the vote to leave the European Union was not a protest against immigration in Britain, as she bowed out as Green Party leader in a farewell speech.

Addressing a rally of supporters on the second day of the party’s annual conference in Birmingham, Ms Bennett accused politicians, including Labour MPs, of misrepresenting the reasons why the public voted for Brexit.

“People did not vote Leave primarily on the basis of opposition to immigration,” she said.“The many politicians, quite a few of them from the Labour Party, who are going around saying ‘this was a vote about immigration and it shows we have to stop free movement’ need to be challenged. Strongly. This was not ‘a vote against immigration’.”

“Lord Ashcroft’s detailed study shows that half of leave voters said the biggest single reason was 'the principle that decisions about the UK should be taken in the UK'. It was only one third who cited their main reason for voting leave 'as control over immigration and borders',” she added.

Instead, she insisted, voters who “say they’re concerned about immigration, when you ask them to explain, most talk about low wages, crowded schools and hospitals, the cost of housing”.

“And even those voters who Those are all rightful concerns. But they are caused by the failed policies of privatisation, of austerity, of financialisation of our economy, of centralisation on Westminster. They are not caused by immigration.”

Her farewell speech comes after Caroline Lucas, the party’s only representative in Westminster, won the leadership contest on Friday on a joint ticket with Jonathan Bartley, the welfare spokesperson, with 86 per cent of members’ votes. It will be the first job-share at the top of major political party in Britain.

Natalie Bennett on her own and Green Party's future

Concluding her speech, Ms Bennett added: “What’s clear is that we cannot continue as we are. If someone tells them Green plans are “unrealistic”, look them straight in the eye and say: “You’re the unrealistic one. Dream on if you think we can continue as we are.”