NEW YORK — Supporters are rallying around Planned Parenthood after renowned breast cancer charity Susan G. Komen for the Cure decided to cut breast screening grants to the reproductive health organization.

Besides $400,000 in smaller donations from 6,000 people, Planned Parenthood is receiving $250,000 from a family foundation in Dallas and a $250,000 pledge announced Thursday by New York Mayor Michael Bloomberg to match future donations.

In Washington, 26 U.S. senators — all Democrats except for independent Bernie Sanders of Vermont — signed a letter calling on Komen to reconsider its decision.

“It would be tragic if any woman — let alone thousands of women — lost access to these potentially lifesaving screenings because of a politically motivated attack,” the senators wrote.

According to Planned Parenthood, its health centers performed more than 4 million breast exams over the past five years, including nearly 170,000 as a result of Komen grants.

Komen, meanwhile, has been deluged with negative emails and Facebook postings, accusing it of knuckling under to pressure from anti-abortion groups, since The Associated Press reported on Tuesday that the charity was halting grants that Planned Parenthood affiliates used for breast exams and related services. The grants totaled $680,000 last year.

Some of Komen’s local affiliates were openly upset, including all seven in California, and at least one top official has quit, reportedly in protest.

Komen’s top leaders, in their first news conference since the controversy erupted, denied Planned Parenthood’s assertion that the decision was driven by pressure from anti-abortion groups.

“We don’t base our funding decisions … on whether one side or the other will be pleased,” said Komen’s founder and CEO, Nancy Brinker, depicting the criticism as a mischaracterization of the charity’s goals and mission.