ABC News' Z. Byron Wolf reports: Senate Finance Committee negotiations for a bipartisan health reform bill got back underway this afternoon with a new deadline. When things reached a perilous moment last Thursday and the six negotiators met alone, no staff, in a cramped office in the Capitol building to find a way forward, they agreed to work through the summer recess to find middle ground. Congress has until September 15. Waiting any longer would put Democrats in danger of not being able to use their ace in the hole – the procedural tactic in the budget process known as reconciliation – to pass a more piecemeal health reform overhaul without Republican support. The Sept. 15 date is written in pencil and not officially announced, it would seem, but hard to move. And this newest deadline is already causing new obstacles among the negotiators. The Democrats seem to realize that September 15 is the date beyond which they cannot continue to negotiate. As Kent Conrad told ABC’s David Chalian and Jon Karl on "Top Line" Friday, “My anticipation is that we will produce a package in September — in the first part of September, the first half of September, and if we don’t we’ll have to go in a different direction." Republican Mike Enzi, however, fired back Monday in a paper statement that he agreed to no such deadline. Said Enzi: “I have not and will not agree to an artificial deadline because I am committed to getting health care reform right, not finishing a bill by some arbitrary date. Improving access to quality, affordable health care for American families is too important to do hastily… We’re making progress, but we still have several significant, outstanding items to work on. I won’t be moved by partisan threats to misuse the budget reconciliation process. I am committed to getting health care reform right,” he said. But it seems like after that date, Democrats, if they want to pass something, will have to fall back on the partisan approach. So Enzi could keep negotiating after that date, but it might be in a very lonely room.