K-Fed is after Britney’s money

Britney Spears’ ex wants her to cough up more child support.

Kevin Federline’s attorney sent a letter to Spears saying that he wanted to discuss how much money he receives monthly, according to The Blast.

The “Toxic” singer currently sends him $20,000 a month for their two sons. That amount was decided on during their divorce — before her Las Vegas residency, where she raked in $475,000 a show. Spears, 36, reportedly brought home $15 million per year from her Planet Hollywood gig, according to the outlet.

Federline did not say how much he now wants, but he previously said that co-parenting with Spears was “really easy.”

Federline, 39, is being represented by Mark Vincent Kaplan — who was busted for a DUI while representing Stephen Collins during his child molestation scandal.

Spears and Federline tied the knot in 2004 and welcomed Sean Preston, now 12, and Jayden James, now 11, before their 2007 split.

Reps for Spears and Federline didn’t get back to us.