A new ad comparing Donald Trump to the advancing threat of coronavirus has been released by an anti-Trump Republican group – among whose backers is the husband of one of Mr Trump’s key aides.

“There’s a virus in the world,” the ad’s voiceover tells the viewer over a montage of empty streets and buildings. “For some people, the virus is easy to see. Others don’t see it at all.

“Some say the virus isn’t that bad. Others say it’s malicious and dangerous.

“Since there are those who still can’t see it, wouldn’t it be smart to tell the truth about the virus?” And then, over a picture of Mr Trump: “Since there is a virus?”

The ad is the work of the Lincoln Project, a campaign organisation founded by a group of Republicans who want to see Mr Trump defeated. One of its founders is George T. Conway III, the husband of Kellyanne Conway, a senior adviser to the president who has worked for him since the days of his 2016 presidential campaign.

Mr Conway has been at daggers drawn with Mr Trump since at least 2017, when he turned down a job at the Justice Department. The two men have frequently traded insults on Twitter, Mr Trump calling Mr Conway a “loser” and “husband from hell”. Mr Conway generally gives as good as he gets.

But in his capacity as a leader of the Lincoln Project, Mr Conway takes a less combative and more high-minded approach to his battle with Mr Trump, who he sees not only as deranged and unfit for office but also as a threat to the very future of the American republic.

In a manifesto published in the New York Times at the end of 2019, Mr Conway and the Lincoln Project’s leaders spelled out the stakes for their work, which is now focused on persuading as many dissident Republicans as possible to vote against Mr Trump in districts that could flip the presidency, Senate or House of Representatives away from him and the party he represents.

“This effort transcends partisanship and is dedicated to nothing less than preservation of the principles that so many have fought for, on battlefields far from home and within their own communities,” they wrote.

“The American presidency transcends the individuals who occupy the Oval Office. Their personalities become part of our national character. Their actions become our actions, for which we all share responsibility. Their willingness to act in accordance with the law and our tradition dictates how current and future leaders will act. Their commitment to order, civility and decency is reflected in American society.