LANSING, MI — Opponents of Proposal 3 recently bought $6.7 million worth of television and radio ads attacking Proposal 3, according to station data collected by the proposal backers.

Clean Affordable Renewable Energy (CARE) for Michigan already has spent $5.7 million on television ads against the proposal to increase the renewable energy standard to 25 percent by 2025, according to data compiled by Rich Robinson of the Michigan Campaign Finance Network. That figure runs through at least Oct. 8.

Proposal backer Michigan Energy Michigan Jobs (MEMJ) has also been tracking its opponent’s spending. It released figures showing CARE spent $6.7 million on network television and radio ads starting this week through November 6th and 5th, respectively, along with cable television ads through Oct. 26.

CARE would not comment on its ad buys.

MEMJ has spent nearly $3 million on television ads according to Robinson's data. The campaign is expected to spend another $5 million to $7 million on ads before the Nov. 6 election.

All told, ad spending could exceed $20 million between the two sides.

The proposal is mostly funded by environmental groups, while the opposition is largely funded by Consumers Energy and DTE Energy, according to campaign finance reports filed in July. The next report is due on Friday.

Email Melissa Anders at manders@mlive.com. Follow her on Twitter: @MelissaDAnders.