Audley Harrison has claimed he will retire if he fails to beat Michael Sprott in London next month.

The 2000 Olympic champion will take on fellow British fighter Sprott in a European title fight at Alexandra Palace on April 9 and is confident he will come through that test.

Harrison, 38, told Sky Sports News: "I'm calling this 'revenge or retirement'.

"If I can't get revenge over Michael Sprott my career can't go forward.

"I know that's the kind of mentality I'm taking into the ring.

"If I don't win this fight I will retire but I'm going to win this fight, no doubt."

Sprott won by knock-out when he faced Harrison in 2007.

He stepped in to take on Harrison again when Poland's Albert Sosnowski pulled out of a planned fight with the Sydney gold medallist, in favour of fighting WBC champion Vitali Klitschko.

Harrison looks back with regret at his previous clash with 35-year-old Sprott.

He said: "Obviously I made some major errors in that fight and Michael Sprott was able to knock me out.

"I've really been looking forward to having the opportunity to avenge that defeat.

"Now I'm getting the chance to rectify my mistakes.

"It's definitely a reality that winning this fight puts me in a position to challenge one of the (world) champions."