The national debate over the labeling of bioengineered foods has shifted to a congressional primary race in south-central Kansas.

Outside money from political action committees is entering the race in its final days. That’s because congressman Mike Pompeo introduced legislation in April that would block states from requiring mandatory labeling of genetically modified foods.

Former congressman Todd Tiahrt has made Pompeo’s bill a campaign issue in his 4th District challenge.

The Washington-based Food Policy Action is spending $40,000 for digital advertising on social media supporting Tiahrt. It is joined by Every Voice Action, which has begun airing the first of $100,000 in television ads on the issue.

Weighing in on the other side of the bioengineered food labeling flap is the American Chemistry Council. It is spending $165,200 supporting Pompeo.