Sen. Dianne Feinstein (D-Calif.) said on Monday that a controversial assault weapons ban will not be part of a Democratic gun bill that was expected to reach the Senate floor next month.

After a meeting with Senate Majority Leader Harry Reid (D-Nev.) on Monday, a frustrated Feinstein said she learned that the bill she sponsored — which bans 157 different models of assault weapons and high-capacity ammunition magazines — wouldn’t be part of a Democratic gun bill to be offered on the Senate floor. Instead, it can be offered as an amendment. But its exclusion from the package makes what was already an uphill battle an almost certain defeat.