The Obama administration renewed a threat Monday to veto a $680 billion defense spending bill if it includes money for two separate engines for the F-35.
Gates said there is no need for two engine suppliers.
"We have looked at the business case a number of times," Gates said. "The general conclusion is that it would cost several billion dollars in addition," and cause headaches for production down the road.
In an era of defense penny-pinching, Gates said, "we feel strongly there is not a need for the second engine."
Having an alternate supplier for one of the most expensive components of the military's next-generation fighter jet would spread defense dollars and jobs across more companies, and more congressional districts.
Stripping the funding toward a second engine supplier would save $560 million. Pratt & Whitney make the current engine, but some are pushing for General Electric to develop another engine, the Fort Worth Star-Telegram reported.
General Electric is the parent company of NBC Universal, the owner of NBCDFW.com.
Congressional leaders have been informed that the president's advisers would recommend a veto if the money for the second supplier stays, Gates said Monday.
The Pentagon calls the F-35 its future workhorse, a mix-and-match platform that can do many things that now require specialized aircraft that cost billions to fine-tune.
But the F-35 is far from cheap. The Congressional Research Service estimates the F-35, also called the Joint Strike Fighter, will cost $246 billion to buy 2,456 planes for the Air Force, Navy and Marines. Including research and other initial costs in the 12-year-old program, the CRS puts the average cost of each plane at $100.1 million.
Other estimates range from $49 million to $62 million a copy when the plane is in peak production.
Congress yielded on another jet program, voting to cut off production of the F-22 as Gates had recommended.
About 2,000 people make parts for the F-22 at Lockheed Martin's Fort Worth facility.