COLUMBUS, Ohio (AP) -- A national union leader says Ohio coal miners pictured in a new ad from the Mitt Romney campaign are those who were required to appear at the Republican presidential nominee's coal-country rally, missing a day's pay.
AFL-CIO President Richard Trumka on Wednesday echoed earlier concern after footage from the August event at the Century Mine in Beallsville in southeastern Ohio was included in Romney's ad.
The ad criticizes President Barack Obama for imposing environmental regulations that have hurt coal production and for a statement in 2008 that new coal-fired power plants would go bankrupt as a result of fees he supported for greenhouse gas emissions.
Romney's campaign didn't immediately respond to a request for comment.
The union sought an investigation last month into the plant being shuttered for the rally.