McConnell Boxer Cruz Paul composite
CNN  — 

Senate negotiators announced Tuesday that they had reached a tentative agreement on a multi-year, multi-billion bill to fund highway construction ahead of a deadline at the end of the month when the current funding expires. But Senate Democrats blocked taking up the agreement right away so they could have additional time to study the deal.

Quick passage of the agreement is also complicated by a pair of unrelated but contentious issues two Republican presidential candidates want to debate as part of the bill – funding for Planned Parenthood and the Export-Import Bank.

“Senators from both parties know that a long-term highway bill is in the best interest of our country. So we’ll continue working together to get a good one passed,” Senate Majority Leader Mitch McConnell said on the floor about the agreement he had struck with Sen. Barbara Boxer of California, the top Democrat on the public works committee.

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Boxer called the agreement a “breakthrough” but details of the deal – including how it would be funded – were not released until after a procedural vote to begin debate was initially scheduled.

In fact, Democrats voted to block starting debate until they had time to pour through the multi-faceted bill that provides funding for highways, bridges and other infrastructure projects and that also includes thorny transportation policy changes that have been difficult to resolve.

“We have a few rules that we follow,” Senate Democratic Leader Harry Reid said after meeting behind closed-doors with other Democratic senators. “One is that we should actually be able to see the bill and read it and discuss it before we’re asked to vote on it.”

Democrats couldn’t say how much time they would need to study the 1030 page bill before beginning formal debate but McConnell said he hoped to vote again Wednesday to begin debate.

If senators get on the bill, Sen. Rand Paul of Kentucky wants to offer an amendment blocking funding for Planned Parenthood, after a controversial video surfaced last week showing an executive with the organization discussing the use of fetal tissue from abortions for medical research.

RELATED: Second Planned Parenthood video surfaces showing alleged selling of fetal tissue

Sen. Ted Cruz of Texas wants to block an amendment by supporters of the recently expired Export-Import Bank, who are trying to revive the federally-funded institution that makes loans to companies overseas to buy American products.

Cruz and other conservatives see it as a government handout from a bank they see as corrupt. McConnell has promised bank supporters they could get an amendment vote on the highway bill and it’s expected to have more than 60 supporters.

Both Paul and Cruz have pledged to go to the mat on their respective issues so it’s unclear how long it will take to work through the bill.

If the Senate passes the bill, it’s unlikely the House, which passed a substantially different highway bill, would quickly accept it. That means the two chambers would probably agree on a short term bill to keep road projects funded until after the August congressional recess.

House Majority Leader Kevin McCarthy urged the Senate to pass the extension of the highway program that the House approved recently, which authorizes spending for roads and bridges through mid-December.

“I think the Senate should take up our short term bill as is and pass that,” he said.

McCarthy told reporters he was withholding judgment on the Senate deal, but said he preferred a long term package that fully paid for the program.

But McConnell said late Tuesday he hoped that the House would be happy with the bipartisan bill the Senate is working on and consider passing it before leaving town for the August recess.

McConnell also threatened to have lawmakers work this weekend in order to speed Senate passage.