MADISON, Wis. — A proposal that began as a bipartisan effort to prevent future delays in the testing of sexual assault evidence kits in Wisconsin but that morphed into a partisan fight appears doomed in the Legislature.

Advocates for sexual assault victims, members of law enforcement and others had worked for years, first with former Republican Attorney General Brad Schimel and then his successor, Democrat Josh Kaul, on a measure that would prevent backlogs in the testing of evidence kits. Wisconsin had a backlog that Kaul used against Schimel during Kaul's successful campaign for attorney general in 2018.

The bipartisan bill was introduced after Kaul took office and the Senate passed it with bipartisan support. But support evaporated in the Assembly, where Republicans introduced a new version that had elements Democrats opposed. Those would require police to notify immigration authorities if sexual assault defendants and convicts were in the country illegally and allow student victims to enter Wisconsin's school choice programs.

The Assembly passed that version of the bill earlier this month with no Democratic votes. On Thursday, Republican Senate Majority Leader Scott Fitzgerald said there is opposition to that proposal among Republicans in the Senate who had backed the earlier bipartisan bill. The Senate passed that one in September. Because of that opposition, Fitzgerald said it was unlikely that any bill to prevent sexual assault test kit backlogs would pass this year.

"I don't have the support for taking up the bill with those amendments in there as we sit here today," he told reporters.

The Assembly was meeting for a final day on Thursday, while the Senate will hold its final day in March. A bill would have to pass both chambers in identical form and be signed by Gov. Tony Evers before it could become law.

In a statement, Kaul faulted Republicans for killing the bill, accusing them of choosing to"prioritize political point counting over justice for survivors and public safety."

The heart of both bills is increased submission and tracking requirements for the sexual assault kits to ensure that collected evidence is quickly analyzed so that law enforcement agencies can bring charges.