WASHINGTON — The House has voted to hold formal negotiations with the Senate on a wide-ranging farm bill that sets policy for farm subsidies and food stamps.

Farm-state lawmakers have pushed the five-year, roughly $500 billion legislation for two years as it has been mired in debates over spending. They are hoping to finish the bill by January, when some dairy supports expire and milk prices could rise.

The Senate passed its farm bill in June, and the House passed two bills that will be combined in the negotiations. One House bill sets policy for farm programs and the other would cut around $4 billion a year from food stamps.

Food stamps are expected to be a contentious issue in the negotiations. The Senate bill would cut just $400 million a year.