Beijing’s ambassador to Brazil has launched a stinging attack on the son of its far-right president, Jair Bolsonaro, after he claimed the Chinese Communist party was to blame for the coronavirus crisis sweeping the world.

On Wednesday, Bolsonaro’s influential politician son Eduardo – who many regard as Brazil’s de facto foreign minister and has close ties to Steve Bannon – enraged Beijing with an incendiary tweet about its role in the pandemic.

“It’s China’s fault,” Bolsonaro claimed on Twitter, retweeting a message that said: “The blame for the global coronavirus pandemic has a name and surname: the Chinese Communist party.”

That remark drew a ferocious rebuke from senior Chinese diplomats, who have become increasingly combative since Xi Jinping – an authoritarian leader regarded as China’s most powerful since Mao Zedong – took power in 2012.

Yang Wanming, Beijing’s top diplomat in Brazil, demanded an immediate retraction and apology for the “evil insult”, while his embassy accused Eduardo Bolsonaro of contracting “a mental virus” during a recent trip to the United States.

“Your words are extremely irresponsible,” the embassy in Brasília tweeted.

“Regrettably, you’re someone lacking both international vision and common sense, knowing neither China nor the world,” the Chinese embassy added. “We would advise you not to be in such a hurry to be the US’ spokesperson in Brazil – you’ll fall flat on your face.”

According to reports in the Brazilian media Yang also retweeted a message that read: “The Bolsonaro family is the great poison of this country.”

The row coincides with a deepening diplomatic row over the disease between Beijing and Washington, which was exacerbated by Donald Trump’s insistence on referring to the coronavirus as “the Chinese virus”.

But Eduardo Bolsonaro’s attack on Brazil’s biggest trade partner has also underscored the pugnacious and volatile turn Brazilian politics has taken under his father’s far-right leadership – even towards key Brazilian partners.

“You should be EXPELLED from the country,” Allan dos Santos, one of the loudest online cheerleaders of Bolsonarismo, tweeted at China’s ambassador on Thursday.

Another prominent Bolsonarista, Bernardo Küster, tweeted: “This shit came from China. The Chinas [sic] lied and were negligent. Don’t trust communists – much less Chinese communists.”

But Chinese diplomats – once regarded as drab and phlegmatic operators – are also increasingly inclined to fight back publicly, as well as privately inflicting economic pain on their detractors.

“We treat our friends with fine wine,” China’s ambassador to Sweden warned last year in the bluntest expression of that new assertiveness. “But for our enemies we have shotguns.”