Director Adam Shankman is struggling to reunite the original stars of Step Up for the next movie in the dance franchise because lead actor Channing Tatum is too busy.

Tatum starred in the 2006 film with his now-wife Jenna Dewan-Tatum, but was absent from the three subsequent sequels.

Shankman is now working on a fifth movie featuring all the franchise's leading stars, but admits he might not be able to get Tatum on board.

He tells New York Post gossip column Page Six, "There will be more (movies). It's (the next film is) going to be a sort of all-star edition of the movies. I'm trying to make sure Jenna Dewan-Tatum is there. But Channing Tatum is booked for two years."

Shankman adds of the couple, which is expecting a baby this year (13), "I like to take credit for that union... because we cast them together."