The leaders of the House Armed Services Committee clashed Thursday on the House floor about whether a proposed amendment to the 2020 National Defense Authorization Act would delay modernization of nuclear-tipped intercontinental ballistic missiles, or make modernization cheaper.

Rep. Earl Blumenauer (D-Ore.) wrote the amendment, which would forbid the Office of the Secretary of Defense from spending 10% of its 2020 budget until the Pentagon reports to Congress about whether U.S. Minuteman III missiles could be extended for service until 2050.

Minuteman III was refurbished after the turn of the millennium and is to remain in service until 2030, when the Pentagon would start replacing the silo-based nuclear missiles with Ground Based Strategic Deterrent (GBSD) missiles. The next-generation missiles would remain in service until the 2080s. 

In a voice vote during a June markup, the House Armed Services Committee stripped the Minuteman III study Blumenauer proposed Thursday out of the lower chamber’s 2020 National Defense Authorization Act.

But on the floor Thursday, Rep. Adam Smith (D-Wash.), the Armed Services chair who called the June voice vote, said the Committee vote “was not overwhelming,” and that “there were a large number of members of the Armed Services Committee who supported the proposal that Mr. Blumenauer is now making.”

Smith argued that, depending on the results of the Minuteman III study, an extension might prove cheaper than plowing ahead with the GBSD procurement.

Republicans led by Rep. Mac Thornberry (R-Texas), the ranking member of the House Armed Services Committee, flatly rejected the need for the study. Thornberry himself said it amounted to “delay by study” for the GBSD program, which is in the final year of a three-year design competition that will end when the Pentagon selects a design from either Boeing [BA], which designed Minuteman III, or Northrop Grumman [NOC].

Thornberry and his Republican colleague Rep. Mike Turner (R-Ohio), the ranking member of the House Armed Services strategic forces subcommittee, said any delay stemming from a study would only bloat the overall cost of upgrading the land-based leg of the U.S. nuclear triad.

After a voice vote in the virtually empty House chamber, Speaker of the House Pro Tem Rep. Henry Cuellar (D-Texas) declared that Blumenauer’s amendment had passed. Turner demanded a voice vote, which the House had not taken at deadline Thursday for Defense Daily.

The House had many more amendments to the 2020 National Defense Authorization Act to consider at deadline. The Senate passed its version of the annual military policy bill in June.