Three Arizona groups have deadlines this week to turn in petitions referring recently passed state laws to the voters in 2014. In each instance, a successful petition drive would block implementation of the law until the election in 14 months.

The measure being most closely watched would put on hold the Legislature's passage of Medicaid expansion under the Affordable Care Act. Called the Health and Welfare Budget Reconciliation referendum, it is sponsored by a Tucson-based group called United Republican Alliance of Principled Conservatives, chaired by former state Sen. Frank Antenori.

As with the other two petition drives, the effort to block the Medicaid expansion needs 86,405 valid signatures. Former state Sen. Ron Gould, a supporter of the effort, told The Associated Press Monday that there is a "50-50" chance the group will have enough signatures.

A second referendum proposal with a Wednesday 5 p.m. deadline is called We the People AZ Against Common Core. It aims to block legislation that would allow school districts to increase their bond indebtedness. There was no word from the sponsors on whether they will have enough signatures.

The third petition drive, with a Thursday 5 p.m. deadline, is sponsored by the Protect Your Right to Vote Committee. It would refer to the voters a series of bills passed in the Legislature this year that change the state's election laws, including a purge of early voter mailing lists and limits on who can collect and turn in mailed ballots. Members of that group said they have the signatures and plan to file Wednesday.