Northrop Grumman Corp. said Monday that it has nearly doubled its estimate of the number jobs that will be created as a result of the $35 billion contract it got from the Air Force to make aerial refueling tankers.

The Los Angeles-based defense contractor increased its estimate of direct and indirect jobs supported by the program to 48,000 up from an initial estimate given last year of 25,000.

The new estimate is based on a Labor Department formula for job creation and comes as members of Congress have threatened to halt funding of the gigantic award due to the effect if will have on domestic jobs.

About 60 percent of the content of the Northrop tanker will come from the U.S. with the remaining work to be done in Europe. Northrop is partnered with the European Aeronautic Defence & Space Co.

Rival Boeing Co. was briefed by the Air Force on March 7 on why it did not win the contract. The Chicago-based company said it had “significant concerns” about the bidding process and said it will decide this week whether to protest the award.

Shares in Northrop were up 19 cents to $79.20 in early trading Monday.