(NBC News) -- A ban on assault weapons won't be included in major gun legislation set to take shape this week -- all but guaranteeing it won't pass Congress.
Democratic Senate Majority Leader Harry Reid, a onetime ally of the National Rifle Association, informed California Sen. Dianne Feinstein on Monday that the proposal to ban assault weapons and high capacity magazines won't be included in a broad package of new gun laws that's taking shape this week and will be considered on the Senate floor in April.
Sen. Dianne Feinstein, D-Calif., and Sen. Ted Cruz, R-Texas, engage in a spirited discussion over the Constitution and gun rights on Capitol Hill Thursday.
"People say well, are you disappointed? Obviously I'm disappointed," Feinstein told reporters Tuesday. Feinstein has worked on gun violence issues for decades.
"The enemies on this are very powerful. I've known that all my life," she said.
Congress passed an assault weapons ban in 1994, but it was allowed to expire when lawmakers didn't renew it a decade later.
The move is a setback for President Barack Obama and Vice President Joe Biden's push for broad new gun control in the wake of the massacre at a Newtown, Conn., elementary school that killed 20 schoolchildren and six adults.
The Senate still plans to vote on the ban, but only as an amendment to the larger gun bill. Feinstein also asked for a second vote on a measure that would just ban high capacity magazines for assault weapons; that's likely to garner more support.
Putting an assault weapons bill into a broad package of gun laws -- instead of insisting that Feinstein offer it as an amendment -- could have helped it earn more votes. But the ban is so controversial, including it would have likely doomed other gun restrictions that have some bipartisan support.
Leaders are now considering how to shape the larger package and plan to release their bill this week. On the table are a bill to broaden background checks for gun buyers, a school safety measure and legislation to make gun trafficking and straw purchasing a felony punishable by up to 25 years in prison.
The gun trafficking and school safety bills were both approved by the Senate Judiciary Committee with bipartisan support.