22 JUMP STREET (15, 112 mins) ****
Starring Jonah Hill, Channing Tatum, Ice Cube, Amber Stevens, Wyatt Russell, Peter Stormare, Jillian Bell, Jimmy Tatro, Nick Offerman. Directors: Phil Lord, Christopher Miller.

With a knowing wink and a profusion of expletives, 22 Jump Street abides by the conventions of a sequel and condemns its dim-witted yet loveable protagonists to relive the plot of the original on a vastly-inflated budget.

That’s no bad thing.

Tongue-in-cheek, self-referential playfulness abounds in this uproarious action-packed comedy, which adheres unabashedly to a winning formula and gleefully colludes with us for various in-jokes and sight gags.

Thus, when Deputy Chief Hardy (Offerman) tells officers Schmidt (Hill) and Jenko (Tatum) they must return to undercover duties, the latter cutely asks, “What if we went to the Secret Service and had to protect the White House?”

Tatum stops short of holding up a DVD copy of his 2013 blockbuster White House Down and flashing an impish grin to camera.

Wonderful on-screen chemistry between the leads powers the picture through the occasional lull and the scriptwriters have a ball increasing the homoerotic undercurrents of the central bro-mance into an unstoppable flood.

“Maybe we should investigate different people,” contemplates Tatum, flashing those big doe eyes at his partner.

“Are you saying you want an open investigation?” replies Hill, heartbroken.

22 Jump Street opens with Schmidt and Jenko investigating criminal mastermind The Ghost (Stormare) and continuing to be a liability to the public and each other.

After a sting to capture The Ghost goes bad, Captain Dickson (Cube) recruits the pair for another hare-brained undercover operation.

This time, they must pose as college students and unmask the suppliers of a drug called W.H.Y.P.H.Y. (Work Hard? Yes! Play Hard? Yes!).

The narcotic has claimed the life of one girl on campus and Dickson wants to prevent W.H.Y.P.H.Y. spreading across the country.

So Schmidt and Jenko adopt their unlikely cover identities and infiltrate different student cliques.

Buff and athletic Jenko becomes a star player on the football team and forges a fraternal bond with kindred spirit Zook (Russell).

Meanwhile, Schmidt dabbles with slam poetry and becomes attracted to spunky student Maya (Stevens), who lives across the hall from the dead girl with her creepy roommate Mercedes (Bell).

22 Jump Street is as preposterous and laugh-out-loud funny as its predecessor, engineering new perils for the dunderhead double-act as they solve the case with characteristic toe-curling awkwardness.

Plot twists aren’t entirely unexpected, but predictability doesn’t spoil our enjoyment one bit as we marvel at Hill and Tatum’s willingness to endure bruising physical pratfalls for our amusement.

Of course, there is a smattering of raunchy gags involving sex toys and male appendages, but the script’s sweetness always trumps crudity.

Hilarious cameos are peppered throughout, even in an extended end credits sequence that suggests Schmidt and Jenko might have a couple more undercover cases in them yet.