Both leaders appeared at a rally in Chicago this afternoon alongside state and local legislators and the victims of gun violence.
Blagojevich and Daley have been pressing for the ban since the federal measure expired more than a year ago.
The law would prohibit the manufacture, possession and delivery of semiautomatic weapons, assault weapon attachments and the 50-caliber assault rifle.
Blagojevich will deliver his State of the State address Wednesday.
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