Wladimir Klitschko is adamant a fight with Anthony Joshua will only take place if the bout includes the WBA heavyweight title. The Ukrainian's clash with the IBF champion is in jeopardy after demanding that he be permitted to the challenge for the vacant world title vacated by Tyson Fury.

Fury vacated the WBA and WBO belts he won from Klitschko last November in order to undergo psychological counselling, after twice cancelling rematches with Klitschko this year. The 40-year-old remains keen to reclaim at least one of the belts, and though he has agreed in principal to fight Joshua in Manchester on 10 December, is yet to commit to the clash.

The WBA must sanction the fight to allow Klitschko and Joshua to contest for the vacant crown, in a bout which could be worth an estimated £30m according to The Daily Telegraph. However, the more likely scenario is both will fight separately before the turn of the year prior to a unification bout in 2017.

"For Wladimir, it is absolutely most important that the WBA will sanction his next fight, regardless of his next opponent," Klitschko's manager Bernd Boente told Boxingscene.com. "Wladimir has always been a very loyal and committed WBA champion and the WBA has always been a very important belt.

"So, now we have to see what the WBA rules as the next step, and hopefully quickly because Wladimir wants to fight this year. For Wladimir it is very important that the WBA belt be on the line in his next fight and I think it shows that for Wladimir, his intentions are not just to cash in. If this fight with Anthony Joshua will not happen this year, then this fight could happen next summer, for example, in a stadium in Germany or England."

The delay in clinching an agreement to fight Klitschko means Joshua's promoter Eddie Hearn has already begun talks with alternative opponents. Mandatory IBF challenger Joseph Parker of New Zealand is set to face Andy Ruiz Jr, while Lucas Browne is expected to challenge for the 'regular' WBA title. "With the hold up from the WBA, we need a little more time, so regardless of if it's Klitschko or not, AJ will return on December 10 in Manchester," the Matchroom chief told Sky Sports.

"We are beginning discussions with other opponents now while crossing our fingers that Klitschko takes the fight, regardless of how many belts are on the line. In an ideal world, there would be as many belts as possible on the line, but I hope he takes up the challenge rather than a soft touch in Germany."