Senator Charles Grassley, the top Republican on the Senate Finance Committee, has decided not to use his senatorial privilege to hold up the nomination of Lynn, for whom the White House had to waive tough new ethics rules.
But Grassley plans to make a lengthy statement about his concerns on the Senate floor, said spokeswoman Beth Levine. Grassley has called the White House waiver a "giant loophole" in the new ethics rules and said it would pave the way for other potential nominees to circumvent the rules.
The Senate Armed Services Committee last week voted to recommend Lynn's confirmation by the full Senate after the panel's top Republican, John McCain, who had also raised concerns about Lynn, said he would not hold up the nomination.
The Senate had hoped to vote on Lynn's nomination on Tuesday, but put off the vote due to questions raised by an unidentified Republican senator.
Lynn was the Pentagon's chief financial officer from November 1997 to January 2001 under former President Bill Clinton and then worked for Raytheon, the Pentagon's No. 6 supplier, as a registered lobbyist from July 2002 to March 2008. He is now a senior vice president for the company.
His nomination drew fire and required the White House Office of Management and Budget to grant a waiver from newly ordered ethics standards just days after the rules were issued by President Barack Obama as one of his first acts in office.
Grassley also raised concerns about Lynn's performance while serving as the Pentagon's chief financial officer, including his approval of Pentagon accounting procedures, an issue Grassley had investigated in 1999.
In a letter dated Feb. 9, Lynn assured Grassley that he would be bound by most provisions of the ethics standards, except those affected by the OMB waiver.
"I believe that my nomination is consistent with the spirit and intent of President Obama's executive order," Lynn said.
Lynn said he also remained bound by provisions in the rules that restrict a government official's ability to take a job in a related industry for certain periods after leaving office. Most people with direct control over acquisition decisions are restricted from taking jobs in a related industry for periods ranging from one to five years.
Lynn has said he will steer clear for a year of decisions involving six arms programs on which he lobbied on behalf of Raytheon if confirmed by the Senate: the DDG-1000 multi-mission combat ship, Advanced Medium-Range Air-to-Air missile, F-15 airborne radar, Patriot missile "Pure Fleet" modernization, the National Reconnaissance Office's Future Imagery Architecture and the Missile Defense Agency's Multiple Kill Vehicle.
Some watchdog groups question whether the ethics restrictions will hamper Lynn's ability to do his job as the Pentagon's second-highest ranking official, a job in which he will sign off on many major acquisition decisions.
Two sources tracking Obama administration nominations said on Tuesday the White House had finished vetting Ashton Carter, a Harvard University professor and former Pentagon official, and was poised to nominate him for the job of chief weapons buyers.
White House officials were unavailable to comment on the expected nomination, which has not raised concerns like those surrounding Lynn's nomination.
If anything, said Mandy Smithberger, an investigator with the non-profit Project on Government Oversight, her organization was worried because Carter did not have acquisition experience.