Disability advocates have lashed out at the federal government Education Minister Simon Birmingham after he thanked his "lucky stars" his children were not disabled.

The minister made the comments in Senate estimate hearings on Wednesday night, where he was grilled about education funding for children with a disability.

"I look at some friends who have children with varying disabilities and I thank my lucky stars that's not me," Mr Birmingham said.

Children with Disability Australia chief executive Stephanie Gotlib​ said the minister's "deeply offensive" comments sent a damaging message to people with a disability.