Boxing fans look set to miss out as Amir Khan and Carl Frampton are both scheduled to fight on April 21.

Khan’s comeback after two years away from the ring is set to clash with Frampton’s make or break fight with Nonito Donaire in Belfast.

With a tilt at the world title awaiting the winner, the latter will be showcased by BT Sport and BoxNation, while Khan’s comeback against a yet to be announced opponent will be broadcast on the same night by Sky Sports.

With Khan’s fight likely to be no more than a warm up for stiffer opposition further down the line, the Frampton bout is likely to be the better contest.

Yet, it is the wider known Khan who could draw more viewers following a stint on TV’s 'I’m a Celebrity', a scenario which has the Irishman’s promoter Frank Warren fuming.

“It’s a stupid decision,” said Warren.

“You wouldn’t have Manchester United and Manchester City playing in separate matches at the same time on two different channels would you? It just shows he [Khan’s promoter, Eddie Hearn] has got no respect for the sport. It’s so stupid.

“What I will say is that we’ve got a real fight in Frampton and Donaire. Let’s face it, Khan will be fighting a stiff whereas we’ve got two live fighters.”

And neither camp will be backing down, despite splitting viewing figures.

“We announced ours first. We’re not going to change the date because Khan is now fighting on the same night,” maintained Warren.

In the scramble for viewers, former super bantam and featherweight world champ Frampton, 30, has wasted little time in the pre-fight hype, proclaiming his bout one of the biggest ever to take place in Belfast.

"Has a bigger 'away' fighter ever come to Belfast before?" he asked BBC Sport.

"A slip-up here and one of us might never fight for another world title again."

"It's a brilliant fight - a four-weight world champion (Donaire) against a two-weight world champion. I think both of us are in the same situation - there's a lot on the line for both guys."

Meanwhile, in an unexpected twist, former world light-welterweight champ Khan rejected overtures from Warren to team up with Hearn, despite years of bad-mouthing between the pair.

“Khan approached me,” Warren explained. “He wanted to fight Manny Pacquiao and that’s something we could have done. We had him [Khan] in his early days and we had some good nights with him, so we made him an offer but he obviously chose another route.

“Khan’s value of himself does not match our value of him – he’s been out of the ring for two years and he’s coming off a knockout loss.

“But he’s done his deal, and good luck to him.”

Khan, 31, has signed a three-fight deal with Hearn’s Matchroom Sport following a brutal knockout defeat – the fourth of his 35-fight career – by Saul ‘Canelo’ Alvarez in May 2016.

And, victories in April and August could pave the way for a December bout against Sheffield’s former IBF world welterweight champ Kell Brook, who is also promoted by Hearn.

Khan added: “It’s all about now rebuilding my career and making those big fights happen again, like [WBA and WBC welterweight champion] Keith Thurman, like Brook, there are big names out there”