Opponents of a new law expanding Medicaid in Arizona say they are scrambling to gather needed signatures by Wednesday's filing deadline.

A group of conservative Republicans has been circulating petitions to temporarily block the law and put the referendum on the November 2014 ballot. Organizer Christine Bauserman said as of Monday evening they had about 81,000 signatures.

Supporters need 86,405 valid signatures, plus a cushion to account for invalid signatures. They are aiming for 92,000.

Bauserman said Tuesday that even if they get the minimum needed by Wednesday's deadline, she will file the petitions.

Gov. Jan Brewer pushed the plan to add 300,000 poor Arizonans to Medicaid through the Legislature with support from all Democrats and some Republicans.

Brewer said the expansion under the Affordable Care Act will bring $1.6 billion in federal health-care money to the state annually and help keep hospitals in rural areas operating.