During the Q&A session, Mr Johnson said that the backstop represented the "incoherence" of Mrs May's strategy towards Brexit negotiations.
When asked whether there should be a snap referendum across Northern Ireland on the contentious backstop, Mr Johnson said that the "only thing that will snap is people's patience". The future PM would have an difficult choice between accepting European law or giving up control of government in Northern Ireland.
"That's a choice I completely reject," Mr Johnson said, adding that he would do whatever he could to energise talks, but urged others to recognise that Northern Irish citizens were "losing out".
Boris Johnson tells NI hustings that backstop was designed by people who wanted to stay close to the EU anyway, and that he would sort out Irish border later, during negotiations for a free trade agreement pic.twitter.com/EfLhX9ENT9— Emma Vardy (@EmmaVardyTV) 2 July 2019
When questioned about failures on part of the Northern Ireland Assembly, he said that both sides should 'get on with it' and that there was a scope for compromise to resolve differences between Downing Street and Stormont.
Whilst the Tory hopeful dismissed outgoing UK prime minister Theresa May's Brexit deal as "dead", he said that the government could salvage some elements of the deal such as citizen rights.
Views on Same-Sex Marriage
Regarding same-sex marriages and abortion in Northern Ireland, Mr Johnson maintained a similar position to Mr Hunt, stating that it was up to the Northern Irish Assembly to decide and that he has supported same-sex marriage in the past, but believed that the UK government should not impose decisions on such matters.
Views on Conservative Party Leadership
Mr Johnson said that he was determined to preserve the Union after Brexit, stating that it was vital to fight for the union and defend it. It was important to fulfil Brexit by 31 October, Mr Johnson said, adding that it would be a "huge relief" to do so and that Conservatives would never recover as a "fighting force until we get Brexit done".
He urged Tories to "get our mojo back" and stand up for Conservative ideas, which he believed "are the right ideas" such as backing 'wealth creators' and entrepreneurs.
Johnson also roasted UK opposition and Labour leader, Jeremy Corbyn, who he accused of siding with the "mullahs of Iran rather than our allies in the United States".
Boris Johnson defends his attendance at the DUP conference saying without the relationship with the DUP, Jeremy Corbyn would be Prime Minister.— Ken Reid (@KenReid_utv) 2 July 2019
The best way to fight Jeremy Corbyn was to 'get Brexit done' and reenergise the Conservative Party, Johnson said whilst highlighting his defeat of London mayoral contender Ken Livingstone.
Boris Johnson launched his bid as the UK's next Prime Minister last month, where the ballots of roughly 160,000 Tory members will decide the outcome of the contest and the winner will be announced on 23 July. The former and current Foreign Ministers are battling for the top position as the final contenders in the race after contenders such as former Brexit secretary Dominic Raab, Home secretary Sajid Javid, Defra secretary Michael Gove, Health secretary Rory Stewart and others were eliminated after three rounds of voting. But the winner will be tasked with implementing the final phase of Brexit by its 31 October deadline and will face opposition from Commons in future withdrawal agreement votes.