Foreign Secretary Boris Johnson delivers his keynote speech on day three of the annual Conservative Party conference on October 3, 2017 in Manchester, England | Carl Court/Getty Images Brexit is ‘not a plague of boils’ says Boris Johnson The foreign secretary said Brexit would free the UK to ‘start being positive about what we believe in.’

MANCHESTER, England — Britain must stop treating Brexit “as though it were a plague of boils,” Boris Johnson told the Conservative Party conference, in a speech that harangued political and media critics of the U.K.’s exit from the EU.

The foreign secretary, who has faced accusations of disloyalty to Prime Minister Theresa May in recent weeks, called for greater optimism about Brexit, saying it would free the U.K. to increase trade beyond the EU and “engage with the world more emphatically than ever before.”

Johnson made a point of praising May — who was not in the audience for the speech — and avoided pushing any of the four red lines on Brexit that he had laid out in an interview with the Sun at the weekend. He said: “[May] won more votes than any party leader and took this party to its highest share of the vote in any election in the last 25 years and the whole country owes her a debt for her steadfastness in taking Britain forward as she will to a great Brexit deal.”

The foreign secretary attacked the Financial Times newspaper and other “British-edited international magazines” for not being “cheerful” about the U.K.’s future outside of the European Union.

“Across the world, the impression is being given that this country is not up to it,” he said. “That we are going to bottle out of Brexit and end up in some dingy ante-room of the EU, pathetically waiting for the scraps but no longer in control of the menu.”

In similar terms, he condemned the opposition Labour Party’s stance on Brexit, warning that they would leave the U.K. in “limbo.” Labour's position, he argued, would leave the U.K. “locked in the orbit of the EU but unable to take back control. Unable to do proper free-trade deals.”

Johnson’s speech, delivered with typical rhetorical flourishes, praised British ingenuity and achievements and called for more optimism about last year’s referendum result, which Johnson played a key role in securing for the Leave campaign.

“It is time to stop treating the referendum result as though it were a plague of boils or a murrain on our cattle, or an inexplicable aberration by 17.4 million people,” he said. “It is time to be bold, and to seize the opportunities — and there is no country better placed than Britain.”

On the U.K.’s prospects on the world stage after Brexit he added: “I am not saying everyone automatically loves us or that everyone completely follows our sense of humor, though a lot more than you might think. But there is a huge desire out there for us to engage with the world more emphatically than ever before.

“And after Brexit, that is what our partners are going to get as this country is freed from endlessly trying to block things in Brussels committee rooms,” he said. “Freed to stop being negative and to start being positive about what we believe in — including free trade.”

Commenting on the speech, Labour MP and member of the Open Britain campaign Chukka Umunna said, “After weeks of hostile briefings, leaks and red lines, Boris Johnson succeeded in saying absolutely nothing of substance about Brexit in his speech today."

“This was his chance to set out his stall on the biggest issue facing our country, and he completely fluffed it," he added.