The U.S. House of Representatives approved an extension of major autism legislation Tuesday evening, but the bill’s future remains unclear.

The Combating Autism Act, which dates from 2006 and allocates millions for autism research, training and infrastructure, will expire at the end of this month if Congress does not act.

An effort to extend the bill for an additional three years was approved by a voice vote in the House on Tuesday.

Just hours before, however, a clash on the Senate floor revealed fresh opposition in Congress to the measure. When the bill’s sponsor, Sen. Robert Menendez, D-N.J., called for his colleagues to give unanimous consent to the autism legislation, a group of Republican senators objected.

“All of us who object support autism research… but it makes absolutely no sense for us from where we sit to try to play scientist and physician,” said Sen. Jim DeMint, R-S.C.

In addition to opposing condition-specific legislation, DeMint, who was joined by Sen. Tom Coburn, R-Okla., in speaking against the bill, said the measure was not necessary in order to continue current research programs which are funded under other appropriations bills.

Following Tuesday’s events, it is unclear what will happen next with the autism bill, which has received broad bipartisan support otherwise.

If the legislation does gain Senate approval, Obama administration officials have indicated that the president is “fully committed” to reauthorizing the act, which calls for $231 million annually to fund everything from autism research to prevalence tracking, education, early identification and intervention programs.

For their part, proponents of the measure, including Autism Speaks and the Autism Society, hailed the House passage Tuesday evening in emails to supporters, leaving out any mention of the hurdles in the Senate.

At the same time, others within the autism community are working against the bill, saying that it focuses too little on services and the needs of adults with the developmental disorder.

“The Combating Autism Act has failed to provide for the direct needs of families and individuals with autism,” said Ari Ne’eman, president of the Autistic Self Advocacy Network.

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