The race for the Tory leadership intensified as two prominent Leave campaigners moved to block Home Secretary Theresa May's path to Downing Street.

Energy Minister Andrea Leadsom insisted she would give Britain its freedom back, as former defence secretary Liam Fox declared leaving the single market was a price worth paying for immigration control.

Ms Leadsom urged those who backed Remain not to be "afraid" of the future as the minister insisted she was best placed to lead tough EU exit negotiations because she - unlike In campaigner Mrs May - believed Britain was best off free from the grip of Brussels.

The former businesswoman also said she knew how to overcome prejudice in a male dominated world.

In a swipe at frontrunner Mrs May, Ms Leadsom insisted she would not use EU citizens living in the UK as "bargaining chips" as she promised their rights should be preserved.

The minister also dismissed calls that she and fellow candidates should step aside to allow a speedy installation of Mrs May as prime minister, stating: "I don't think we should have any sort of coronation."

Ms Leadsom said her business career gave her key skills for the role of a prime minister dealing with Brexit talks.

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"I know how to strike a deal in a tough negotiation. And I know, as a woman, how to succeed in a man's world and how to fight the unfortunate prejudice that many working mothers still experience," she said.

The minister would not be drawn on when she would invoke Article 50 of the Lisbon Treaty which sets withdrawal from the EU in train, but insisted immigration would be a main focus of talks as she said there was no need for an early general election.

"We want to be able to control the numbers that are coming here. Freedom of movement will end, and the British Parliament will decide how many people enter our country each year to live, work and contribute to our national life."

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Answering questions after her leadership launch, Ms Leadsom said she did not recognise descriptions of her as a "disaster" while City minister.

In a rival bid for the anti-EU vote in the Tory leadership contest, Dr Fox said immigration was key to the Brexit deal.

"I do not believe that you need to be in the single market to sell into the single market. And if the price of the relationship with the single market is free movement of people, it's a price I'm not willing to pay," he said.

Dr Fox said he would pull the UK out of the European Union on January 1 2019 after triggering Article 50 to begin the process this year, and ruled out both a snap general election and a second referendum.

"We cannot lose momentum and risk the derailing of the British people's decision by stealth," he said.

The interventions came after Foreign Secretary Philip Hammond hailed Mrs May's "determination in standing up to vested interests" as he threw his support behind her campaign and warned the status of EU citizens in the UK would be a matter for negotiation.

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As the race for the Tory crown stepped up a gear, Boris Johnson's ex-campaign chief, Ben Wallace, launched a highly personalised attack on Justice Secretary Michael Gove.

In an article for the Daily Telegraph, the Northern Ireland minister said: "When I was a government whip and Michael was the chief whip, the office leaked like a sieve. Important policy and personnel details made their way to the papers. Michael seems to have an emotional need to gossip, particularly when drink is taken, as it all too often seemed to be."

Mr Johnson claimed Remain supporters have been consumed by the type of "hysteria" last seen after the death of Diana, Princess of Wales, since Britain voted to leave the European Union.

With Work and Pensions Minister Stephen Crabb also in the running, the first round of voting among Tory MPs to decide which two candidates go to the membership in the leadership run-off begins on Tuesday.

Asked whether the new leader should not be someone who campaigned for the Leave side, Defence Secretary Michael Fallon - who is backing Mrs May - told BBC Radio 4's World at One: "We're all Brexiters now, we have to be. Theresa May has been crystal clear that Brexit means Brexit. There's not going to be any fudging, there's not going to be another referendum."