The prospects of passing a long-term extension to federal highway and transit programs before the end of the month are evaporating, and House and Senate negotiators face a make-or-break week if they want to get a bill done.

Democratic and Republican aides in both chambers privately acknowledge that with negotiations stalled — and the House out of session next week — getting a bill done before the programs expire at the end of the month is increasingly unrealistic.

“There will be a lot of discussions this week that will kind of tell us where we are,” a Senate Republican aide said, adding that, “June is going to be really tough. … July is really the question.”

A House Democratic leadership aide agreed, warning that the negotiations “don’t sound like they’re making much progress.”

The tension, and lack of progress, has inevitably led to recriminations, albeit in largely private settings.

Despite her rosy public pronouncements, Senate Environment and Public Works Chairman Barbara Boxer, who is leading the conference committee on the legislation, has become increasingly pessimistic.

Late last month, the California Democrat was positively ecstatic about the progress of the conference, telling reporters that “we are making very solid progress. I would say great progress” and that “I believe we are going to have a bill” before the June 30 deadline.

That assessment took most involved in the conference by surprise, with many saying that there had been virtually no agreements on compromise language on basic parts of the bill, let alone big-ticket items such as the Keystone XL oil pipeline.

But during a conference call with stakeholder groups last week, Boxer dropped her upbeat attitude, acknowledging that little in the way of concrete progress had been made — and blaming the struggles on Speaker John Boehner and his leadership team.

Boxer had spoken glowingly of the Ohio Republican last month, and her
U-turn made Republicans bristle.

“Everyone is calm, but there’s frustration on the House side that Senate Democrats aren’t really interested in negotiating,” a House GOP leadership aide said.

Republicans insist part of the problem is Boxer’s belief that House and Senate Republicans are on the same page and that if Senate Environment and Public Works ranking member James Inhofe (R-Okla.) can bring along a huge chunk of his Conference in the Senate, Boehner should be able to persuade enough House Republicans to go along with the bipartisan Senate bill.

But, as one Republican aide pointed out, “Bipartisan doesn’t mean bicameral. … [Boxer] thinks we should just roll over and pass the Senate-passed bill. And that’s just not going to happen.”

With talks crumbling, Boxer had indicated she would float her own version of a “compromise” conference report this week.

However, several Republicans said it now appears the Californian has backed away from that idea and will instead release a less comprehensive set of proposed compromises to consider.

“They’re trying to figure out how to do this,” a GOP aide said.

Republicans said that given the importance of this week’s talks, it would be best not to lay down a hard marker.

“If we want to get it done, we need to make some real progress this week. And Sen. Boxer rolling out her own version of a draft compromise conference report isn’t doing that,” a House Republican aide said.

Boxer’s decision to back off seems at least in part a result of the efforts by Inhofe to bridge the differences between Boxer and House Republicans.

According to the Senate GOP aide, Inhofe is “working very closely with Boxer and with the House Republicans” and is trying to keep everyone calm and focused on getting a bill done.

Inhofe is, at least for now, also trying to stay above the back and forth between Boxer and House Republicans.

“He’s not going to engage in that game. … He thinks it’s essential to get a transportation bill done,” the aide said.

In an interview Monday, Inhofe downplayed his role as a peacemaker or facilitator in the talks, saying simply, “What I’ve attempted to do is contact personally all of the Members of the House who are on the conference that I did not serve with” and discuss the need for a long-term extension.

“It’s a mistake sometimes to draw a line in the sand … instead of just sitting down and talking over a situation,” Inhofe said, explaining that he has sought to impress on the House freshmen that as a conservative, “there is a conservative position in this. And that is to have a bill. Because if you don’t have a bill, there’s only one other choice — you have to do extensions.” And that, Inhofe said, results in “throwing away a third of the money that should be spent on highways. And I just can’t let that happen.”

And so far, Inhofe said, he thinks House Republicans have been open to his efforts.

“They were very receptive to the idea of a significance of a transportation bill,” he said.

Inhofe also acknowledged that Boxer has been frustrated with the pace of the negotiations.

“I think Barbara understands that, but she’s just a little less patient,” Inhofe said.

Still, he remained positive that he and Boxer are working toward a solution.

“She really and truly wants a bill. Maybe she felt perhaps a slight change in approach might help,” he said.