SPICE GIRLS GO UNDER THE KNIFE TO GIVE THEIR POPULARITY A BOOST

WHEN THE GOING gets tough, the Spice Girls get going to their plastic surgeon.

Plagued by D-cup-sized problems — including miserable sales for their new album — one former and two current members of the pop group recently nipped off to get a little tuck.

Since they’re not making hits, here’s how some of them are making headlines:

Posh Spice figured what she needed was bigger boobs — so she upgraded her implants to jumbo.

Curvy former Ginger Spice thought her hips and stomach were too big, so she slimmed down — with liposuction.

Scary Spice got scared by her supersized silicone breasts, so she had her implants removed.

First to unveil her overhaul was Victoria “Posh” Beckham. “Those boobs just stood out,” marveled a regular at a restaurant where Posh’s latest supersized chest made it’s first public appearance. The 26-year-old had her first breast implants in 1999.

Next Geri “Ginger” Halliwell, who left the group for a solo career in 1998, showed off HER new body — slimmed by $15,000 worth of liposuction to trim fat off her chin, upper neck, stomach, hips and thighs.

Geri — who once suffered from binge eating and bulimia — shed an amazing 28 pounds through surgery in L.A., a low-carb diet, and a tough workout regime. But now friends fear the once voluptuous 28-year-old has gone too far — because recently she’s been fainting. “We’re very concerned,” confided a close pal.

Finally, “Scary” Mel B had surgery to get rid of a pair of breast implants that became hard and shapeless.

Pop sources say Mel is desperate to jump start her career. A massive divorce settlement to her hubby has drained her bank account and she tanked as a solo performer.

— JOHN COOKE