Boris Johnson, the favourite to become Britain’s next prime minister, has been described as a security risk by supporters of his rival in a contest that is starting to heat up. Ministerial allies of Jeremy Hunt say Mr Johnson does not deserve to lead Britain and could be vulnerable to blackmail from foreign powers after allegations about his private life. Reports emerged from <em>The Guardian</em> newspaper on Friday evening of "screaming and banging" noises from Mr Johnson's south London home, shared with his partner, Carrie Symonds. When asked to explain the reports, he refused to answer. “I don’t think people want to hear about that,” Mr Johnson said. The two contenders went head to head in Birmingham, Britain’s second city, amid a deeply divided government and a parliament at gridlock over Brexit. Mr Johnson wants to “get Brexit done” as soon as possible, he said. “My ambition is to unite this country and our society. Let’s take Britain forward,” he told a conference of Conservative Party members. “We need to discover a new confidence in our country.” Mr Hunt said there was the possibility of “no Conservative government, and maybe even no Conservative Party” if members elected the wrong person. He warned members that a populist candidate could not oppose a “hard-left populist” in Jeremy Corbyn. “I will never provoke a general election before we have left the EU,” Mr Hunt said. He said he would leave the EU with no deal but did not prefer it. Mr Hunt said he wanted to bring changes to the “Irish backstop”, an insurance policy to avoid a visible border between Northern Ireland and the Republic of Ireland. He said it was possible to make changes to Britain’s withdrawal agreement with the EU by the deadline of 31 October. Mr Hunt previously said he would not rule out an extension, although during the leadership conference debate said he would leave the EU with no deal if necessary. Mr Johnson said he would leave without the £39 billion settlement agreed to by the UK to pay the EU as part of negotiated deals led by departing Prime Minister Theresa May. He advocates a no-deal if Britain cannot sign off an agreement by 31 October with the EU. Mr Hunt is the UK Foreign Secretary and campaigned to remain in the EU during the 2016 referendum. Mr Johnson led the campaign for Brexit and is a widely popular figure within the Conservative Party. Confirmation of who will become Britain’s new leader is expected to be announced in the week starting July 22.