Barack Obama sharply condemned the healthcare plan unveiled by Senate Republicans on Thursday as a “massive transfer of wealth” to the rich, at the expense of poor and middle-class Americans.

In a Facebook post hours after the Republican bill was made public, the former president made some of his most pointed comments since leaving office in defense of what remains the most signature accomplishment of his two terms.

“The Senate bill, unveiled today, is not a healthcare bill,” Obama wrote. “It’s a massive transfer of wealth from middle-class and poor families to the richest people in America.”