Opponents of the campaign aimed at overturning Michigan's revised emergency manager law have until April 9 to challenge voter signatures turned in on petitions supporting the repeal effort.
The deadline for challenging signatures that may be invalid was set this week by state election officials.
Election officials are reviewing signatures turned in by a group called Stand Up for Democracy. The group wants to give voters a chance to overturn Michigan's 2011 emergency manager law during the November election.
The group turned in petitions containing 225,885 signatures. The coalition must have at least 161,305 valid voter signatures to make the ballot.
State election officials are expected to determine by late April whether enough valid signatures were filed.