No Labels has received corporate donations for over a decade, a dive into political disclosures reveals.
Progress Pinellas PAC has spent $4.7 million on ads and mailers attacking Republican candidate Anna Paulina Luna.
The bill would make it a crime for regulators to reveal the donors behind dark money groups trying to influence the state's elections.
The companies' donations appear to contradict their public statements in support of voting rights.
Lawmakers in 24 states have introduced restrictions on ballot initiatives after voters passed measures last year including legalizing marijuana and raising the minimum wage.