Tyson Fury has challenged Anthony Joshua to be his first opponent since defeating Wladimir Klitschko in November, 2015.
Fury called out Joshua in a series of tweets which read: "As a sporting challenge I Lay Down the challenge for Anthony Joshua to fight me in my first fight back in over 2.5 years!"
"I'm the best heavyweight on the planet come prove I'm not? The ball is in your court don't let your fans down CHAMP."
Joshua, the WBA 'super' and IBF champion, has been in talks over a fight against fellow unbeaten heavyweight Joseph Parker.
Alexander Povetkin is mandatory challenger to Joshua's WBA belt following his win over Christian Hammer in December.