PORTLAND, Ore. — A ballot measure that would require labels on genetically engineered foods is now the costliest ballot measure in Oregon history.

A $4.6 million contribution by an out-of-state agriculture giant has pushed the total past the record set seven years ago.

Both sides of the battle over Measure 92 have raised and spent a record amount. Contributions to both campaigns totaled $23 million — a number that’s likely to grow in the 10 days before the Nov. 4 election. The two sides reported spending about $19 million.

The previous record was around $16 million collected and spent for a 2007 fight over a proposed hike in tobacco taxes to pay for children’s health care. That measure failed.

Opponents of the GMO labeling measure reported $16.3 million in contributions, which is more than twice the contributions of supporters, who have received $6.6 million.

Their money comes mostly from large food producers and biotechnology companies. According to filings with the Oregon Secretary of State’s office, the measure’s single largest contribution — $4.6 million — was reported this week and came from Iowa-based agribusiness DuPont Pioneer. The St. Louis-based biotechnology firm Monsanto previously gave $4 million.

Big donors to the Yes campaign include natural foods companies. Both the California-based Dr. Bronner’s Magic Soap and the nonprofit Center for Food Safety donated a little over $1 million.

Similar measures in California and in Washington state failed narrowly in recent years after millions of dollars were spent, mostly by labeling opponents.

The anti-labeling campaign spent about $45.6 million in California, compared to $8.7 million by labeling supporters.

In Washington state, where the ballot contest went on record as the costliest in state history, opponents spent about $22 million, compared to $9.8 million collected by the pro-labeling groups.

If adopted, the measure would require manufacturers, retailers and suppliers to label raw and packaged foods produced entirely or partially by genetic engineering. The measure would not apply to animal feed or food served in restaurants. It would be effective January 2016.

Labeling supporters say there aren’t enough studies on the impacts of GMOs, so consumers have a right to know if they are eating them. Critics say mandatory labels would be onerous and would mislead consumers into thinking engineered ingredients are unsafe, which scientists have not proven.