However she made repeated calls for Brexit in the run up to the referendum

Vote Leave campaigner Andrea Leadsom previously claimed that breaking ties with Brussels would be a 'disaster'

Tory leadership candidate Andrea Leadsom has been branded a hypocrite after dramatically changing her stance on Brexit.

The Energy Minister campaigned for a Leave vote in the EU referendum – but previously claimed that breaking ties with Brussels would be a ‘disaster’, The Mail on Sunday can reveal.

Three years ago, Mrs Leadsom – the leading rival to Theresa May’s bid to become the next Prime Minister – said: ‘I’m going to nail my colours to the mast here: 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.

‘Economic success is the vital underpinning of every happy nation. The wellbeing we all crave goes hand in hand with economic success.’

Mrs Leadsom has been using her more recent support for the Leave campaign to bolster her bid for the Tory crown, saying the party should be led by a Brexiteer as the UK negotiates with Brussels.

She made repeated calls for Britain to leave the European Union during the referendum campaign, when she dismissed David Cameron’s predictions of economic disaster outside the EU as ‘Project Fear’.

Yet that stance seems at odds with the dire warnings she issued at the Hansard Society’s Annual Parliamentary Affairs Lecture on April 23, 2013.

A prominent Remain campaigner said last night: ‘Mrs Leadsom must answer the charge of double standards.’

However a spokesman for Mrs Leadsom denied she was guilty of hypocrisy.

She said: ‘These remarks have been taken completely out of context.

Andrea Leadsom campaigned for a Leave vote in the EU referendum - but three years ago said leaving would lead to 'economic and political uncertainty'

‘Andrea’s position is and has always been that without fundamental reform, the UK could not remain in the EU.’

The controversy is another extraordinary twist in the bitter Tory leadership contest.

Mrs Leadsom has been tipped to go head-to-head with Home Secretary Theresa May for the next Tory leader – although there is a growing mood in the party that other candidates could stand aside to allow Mrs May to become Prime Minister as early as this week to avoid opening up deeper divisions.

The Energy Secretary’s warnings about Brexit emerged 24 hours after she took a swipe at Mrs May, arguing: ‘If we want to make a go of it, then we need somebody who believes in it.’

She opened her 2013 lecture by stating: ‘The EU without Britain is like fish without chips’ – but warned that the body needed major reforms, for Britain’s continued membership to be ‘sustainable’.

She said democratic consent for the EU in Britain was ‘wafer thin’ and had to be improved, then listed a series of complaints from red tape to laws that meant edible fish were thrown back in the sea.

Mrs Leadsom is the leading rival to Theresa May (pictured) in the battle to become the next Prime Minister

However, nine minutes into her speech she made it clear she believed leaving would be an ‘economic disaster’ for the UK – and at no point did she contradict her grave warning.

The speech was disclosed as:

A Mail on Sunday Survation poll showed Mrs May on course for a clear victory;

Boris Johnson told allies he had been a ‘fool’ to trust fellow anti-EU campaigner Michael Gove before his betrayal;

Mrs May spoke for the first time of her and husband Philip’s heartbreak at not being to have children – telling The Mail on Sunday how they sought help with the problem, but in vain.

Tory MPs are set to whittle down the contenders – Mrs May, Mrs Leadsom, Mr Gove, former Defence Secretary Liam Fox and Work and Pensions Secretary Stephen Crabb – to a final two in votes on Tuesday and Thursday. The party’s 125,000 members will then choose between the final two.

Is Andrea Leadsom another casualty of Brexit, asks IAN BIRRELL

They came together in common cause to pull Britain out of Europe. But one by one they stumbled in their attempts to seize the Tory crown.

First Boris Johnson saw long-held ambitions dashed by back-stabbing fellow Brexiteer Michael Gove.

Then the Justice Secretary, making his own bid for power, discovered Westminster colleagues distrusted him after the brutality of his betrayal.

So internal party critics of David Cameron, many of whom had long sought his ousting, suddenly coalesced around a new champion, Andrea Leadsom.

Brexiteers such as Chris Grayling (pictured) are backing Mrs May as the next Tory leader

Never mind that Leadsom was a little-known Energy Minister whose claim to running the country seemed based largely on one assured performance in a Brexit debate.

For the hard Right, that was enough. They are determined to stop Theresa May – who quietly backed Remain – from seizing power.

So they promoted this former banker as the tough-talking inheritor of Margaret Thatcher’s mantle.

She shared their social conservatism, failing to support gay marriage, and is a fierce supporter of the free market.

Thatcher did not stand for the leadership in fury at failing to get written assurances of a top job from a bumbling colleague such as Boris. Yet this snub seems to have been enough to persuade Leadsom to shoot for the nation’s highest office.

Aged 53, this committed Christian has only been in Parliament since 2010 after 25 years in finance, although she first developed her political ambitions 40 years earlier.

Now it emerges that having campaigned with passion about the ‘opportunities’ offered by Brexit, she may have taken a rather different tack in the past and admitted it would be a disaster for the economy.

One more unedifying twist is a depressing saga that has put another stain on the soiled image of Westminster, with deception, hypocrisy and lies.

Behind Brexit lay the desire of some Tory malcontents to reclaim their party from Cameron’s moderate wing. Little wonder it has been called a Right-wing coup; Europe was merely the means to achieve their aims.

One of those involved told me they planned to call for Cameron to resign in the event of last year’s General Election resulting in another Coalition. Their plot was postponed after his shock victory.

It’s no surprise to see that Leadsom’s backers include Iain Duncan Smith, the worst Tory leader in modern memory, whose embittered Cabinet resignation three months ago effectively fired the starting gun on this crisis.

More emollient Brexiteers such as Chris Grayling are backing Mrs May. The Leader of the House argued publicly and privately for Cameron to stay regardless of the referendum result, to ensure stability.

World events have shown how civil wars spiral out of control. As these people play a self-serving game of thrones, the country’s stability lies in ruins.