The biggest heavyweight fight in British history may not happen on British soil, due to the ongoing effects of the COVID-19 pandemic, warns promoter Eddie Hearn.

Shortly after Hearn’s ace client Anthony Joshua downed Kubrat Pulev by ninth-round stoppage of a mandatory defense at the SSE Arena in London on Dec. 12, the attention of the boxing world shifted once more to a potential heavyweight unification clash between Joshua and countryman Tyson Fury.

It seems like a no-brainer for the fight to take place in England, where both fighters occupy a lofty position in the country’s sports stratosphere, but given the current climate that may not be realistic. Recently, prime minister Boris Johnson issued another emergency lockdown (Tier 4) in response to a new, rapidly-spreading variant of the coronavirus.

"Obviously we all would like this fight to take place in the UK but you've seen London go into Tier 4 now,” Hearn told Sky Sports, who added that negotiations with Fury’s team, which includes promoters Bob Arum and Frank Warren, have been so far “positive.”

Without a sizable crowd to satisfy the outsize purses that both Joshua (24-1, 22 KOs) and Fury (30-0-1, 21 KOs) would command, Hearn believes he would be hardpressed to stage the fight in the UK.

"We had a crowd on Saturday [for Joshua's win over Kubrat Pulev] but that has been taken away for the time being,” Hearn said. “There are a lot of unknowns in that respect. Both fighters will have to take a significant reduction in purse for this fight to take place in the UK, unfortunately. Probably half and, without a crowd, maybe 80 percent.

"Really, to give us any chance, we need a full capacity in the UK.”

Hearn has shown in the past that he is not opposed to going where the most money is. Most notably, he staged the Joshua-Andy Ruiz rematch last year in Saudi Arabia, who put up a a gargantuan site fee. Though he received plenty of backlash from many human rights organizations, Hearn defended his decision by pointing out that his only job as a promoter is to make the most money for his fighter; to do so otherwise would be a dereliction of duty.

"We want to make sure this fight goes ahead for both fighters,” said Hearn. “Both camps have a responsibility to maximize the revenue for their biggest fight–this is the pinnacle of their careers, the biggest moment, nothing will ever beat it.

"At the same time, we all recognize this is two Brits fighting for the undisputed championship of the world. If there is a way to do it in the UK? Fantastic."