Tory leadership contender Andrea Leadsom said leaving EU would be 'disaster' – then campaigned for Brexit

'I think it would be a disaster for our economy and it would lead to a decade of economic and political uncertainty at a time when the tectonic plates of global success are moving'

Andrea Leadsom, who has likened herself to Margaret Thatcher in her bid to be the next Conservative leader, said that leaving the European Union would be a "disaster" – despite being one of the leading voices in the Brexit campaign.

The junior energy minister, who is also emerging a serious contender in the Conservative leadership contest, said in a recording three years ago at the Hansard Society’s annual parliamentary affairs lecture that she was going “to nail my colours to the mast here”.

In the recording, obtained by the Mail on Sunday, Ms Leadsom added: “I don’t think the UK should leave the EU. I think it would be a disaster for our economy and it would lead to a decade of economic and political uncertainty at a time when the tectonic plates of global success are moving.

“Like the rise and fall of the Roman and Greek Empires we are seeing the rise of the Asian and South American economies at a time when our own future is less certain. And to be honest economic success is the vital underpinning of every happen nation. The wellbeing we all crave goes hand in hand with economic success.”

A spokesperson for Ms Leadsom told the Independent that the recording was “taken completely out of context.” It is “complete nonsense,” they added.

Mrs Leadsom defended her statement on the Andrew Marr Show: "It has been a journey.

"When I came into Parliament, like most people in the country I'd grown up as part of the EU and it's absolutely part of our DNA and I came into Parliament, set up something called the Fresh Start Project, which took hundreds and hundreds of hours of evidence about how the EU impacts on the UK - on everything from immigration to fisheries and so on.

"During that process I travelled all across Europe with lots of parliamentary colleagues - up to 100 Conservative colleagues supporting this work - to try and get a really decent, fundamental reform of the EU."

According to the newspaper she opened the lecture by saying that the EU, however, needed major reforms in order for it to be “sustainable”. Ms Leadsom added that the democratic consent for the EU in Britain was “wafer thin”.

Meanwhile, Ms Leadsom, a former City worker, likened herself to Margaret Thatcher and praised the late Prime Minister’s ability to mix toughness with “personal warmth” in an interview with the Sunday Telegraph. “As a person, she was always kind and courteous and as a leader she was steely and determined,” she said.

“I think that's an ideal combination - and I do like to think that's where I am.”

It comes as the most recent polling of the Conservative leadership contest places Theresa May, the Home Secretary, as racing towards victory in her bid to succeed David Cameron. Ms May was backed by 60 per cent of Tory voters, with Mr Gove second on 10 points and Ms Leadsom on six, according to the ICM poll for the Sun on Sunday.

Among party members, who will vote to decide the winner of the leadership contest, some 46 per cent say she would make the best Prime Minister. She has also been backed by more MPs, who select the final two candidates to go on to the ballot paper.

An assured performance in the televised debates during the referendum campaign earned Ms Leadsom praise among Leave MPs in Westminister