Washington’s most powerful business lobbyists patted each other on the back this week after an intense lobbying campaign helped water down proposed legislation that will make the national security review process tougher for foreign companies buying sensitive US assets.

But despite the initial elation, business groups on Friday were quick to point out that a bill that was unanimously approved by the Senate banking committee on Thursday still posed significant problems for US and foreign companies and threatened to chill foreign investment in the US.