Thackray has struggled for form with Hull this season

The transfer was originally set to take place at the end of the season but the Great Britain international has been allowed to leave early.

Hull coach Peter Sharp said: "We think it's best for both parties if Jamie plays the rest of the year at Leeds."

Thackray, 26, has signed a three-year deal with Leeds.

"We haven't seen the best of him this season because of a combination of travelling and family issues," added Sharp.

"He's been a very good player for this club over the last year and half and we wish him all the best."

Leeds coach Tony Smith is looking forward to working with Thackray.

"He is an explosive player who makes plenty of impact in games and he will certainly add to the depth of our squad," he said.

"Despite everything he has already achieved in his career, I believe he has not yet reached his full potential.