The specter of a curb on tax breaks for charitable donations as part of a long-term deal to reduce the federal budget deficit is spurring a fundraising and giving rush, according to The Wall Street Journal.

National nonprofits such as Feeding America and the Leukemia & Lymphoma Society are ramping up solicitations and suggesting contributors maximize gifts ahead of a possible budget deal that could limit deductions. In addition, wealthy taxpayers are shifting money into donor-advised funds to secure tax breaks at current levels.

Proposals to lower the top rate for charity tax breaks or include them in an overall cap on deductions have taken a prominent place in the “fiscal cliff” budget talks, prompting a major Washington lobbying effort by nonprofit leaders.