British boxing fans have endlessly clamoured for the bout, with a deal finally looking close.
The northern boxers are expected to trade blows in either February or March next year, according to both fighters’ promoter Eddie Hearn.
It looked as if the match-up would never happen when Khan took a two-year hiatus from the sport after his brutal knockout loss to Saul ‘Canelo’ Alvarez in 2016.
‘King Khan’ has fought twice this year, however, most recently against Samuel Vargas in September.
After gaining a unanimous points decision over the Colombian, Khan expressed his desire to fight Manny Pacquiao before taking on Brook, who was ringside.
That wish is looking increasingly unlikely, however, as Hearn pushes for a grudge match between the pair in late winter.
With gritted teeth, Brook has agreed to drop back down to welterweight (147lbs) to make the fight happen.
Khan recently threw a spanner in the works when he claimed that the naturally-bigger Yorkshireman had agreed to a rehydration clause, though.
That would mean both fighters must weigh up to 147lbs one day before the bout and can’t weigh more than 157lbs on fight night.
It is common practice under IBF regulations, which Brook had to abide by during his 33-month reign as welterweight world champion.
But as the fight would be a domestic bout there is no obligation for Brook to agree to such a term, and he denied ever doing so.
Hearn also admitted in an interview with iFL TV: “That’s not been discussed. Would [Brook] do it again? Probably not.”
It emerged recently that Canelo and Rocky Fielding have agreed to a rehydration clause, as the former moves up to super middleweight for the first time.
Khan responded to that news story on Twitter, posting: “2nd day weigh In. Brook fought under IBF 10lb rule for few fights.
“I want the brook fight at 147lbs with a 10lb rehydration limit. All the top fights do it. Give the fans the fight they want.”
Brook, perceiving Khan as trying to pin the protracted negotiations on him, replied to the tweet with three laughing faces and also said: “Couple of things for you to Khansider you chinny clown.
“1) There’s no IBF title on the line 2) Canelo is moving up a weight class.
“The fight fans know the only clause you’re really interested in is the get out clause! #TooShookForBrook.”
It is expected that Brook will have a tune-up fight on December 8 in Sheffield, but no card has yet been announced.