While Republicans accuse Democrats of looking for excuses to block the bill, they did not dispute that some of the stipulations they added favored Republican policies and points of view.
Senate negotiations are centered around $1.1 billion in funding to fund the federal government's response to the virus, the amount included in the Senate's original bill to respond to the virus and the conference report negotiated by top appropriators in both the House and the Senate.
One of the biggest controversies involves Democrats' opposition to language, backed by Republicans, that they say would prevent Zika funds for abortion providers like Planned Parenthood, mainly in Puerto Rico.
The Democratic leader said the tangible progress on the two issues was positive enough that he dropped his threat Tuesday to shutter action in Senate committees to force action on Merrick Garland's stalled Supreme Court nomination. They cared more about Planned Parenthood than they did Zika.
Hoyer said Republicans intentionally added "poison pill" measures that would force Democrats to reject the bill so that they could spend the summer blaming them for blocking the legislation. The Senate could recess until after the November elections as soon as next Thursday, Cornyn said, although "it would take all the stars aligning in a ideal way with no intervening influence". But these mask their real concern: Planned Parenthood.
"If $1.1 billion is passed by the Senate on a bipartisan basis and it were put on the floor I think it would pass", Hoyer said. At least 16 babies have been born in the United States with birth defects linked to the virus.
This bloc of conservatives, along with several outside advocacy groups on the right are arguing that Congress should pass a funding bill that lasts through the spring.
Federal funds keeping agencies open expire September 30.
The World Health Organization says the outbreak of Zika remains an worldwide health emergency and that while the virus continues to hit new countries, experts still aren't sure how big the risk is that pregnant.
They just returned from a seven-week break and lawmakers are still stuck on finding a way to fund the fight against Zika.
"Let's stop this monkey business", Nelson said, on the Senate floor.
The CDC also is advising pregnant women not to travel to an area where active Zika transmission is ongoing, and to use insect repellent and wear long trousers and long-sleeved shirts if they are in those areas.