Rep. Lou Barletta, Pennsylvania’s Republican candidate for Senate, criticized Democratic challenger Sen. Bob Casey on Sunday for running a “hurtful” and “insensitive” attack ad using sick children while Barletta’s own grandchild is undergoing chemotherapy.

“Bob Casey just released an insensitive and personal attack ad accusing Lou Barletta of wanting to rip away health care from twin children with cancer, after Lou personally told Casey of his 18-month-old twin grandson currently undergoing chemo for cancer,” Barletta tweeted, with a video response included.