Typically, the appropriations bill aren’t finished until September or October, so it’s not clear whether Leahy means then or now. It is possible that the Congress could pass legislation prohibiting the administration from giving any more of this year’s aid to Egypt, and/or cutting off all arms sales, etc.

Senator Leahy (D-VT), who made this threat, is the top Democratic Senator in charge of foreign aid. If he wants Egypt to be cut off, he runs a very good chance of making it so. More from ThinkProgress.