Jennifer Lawrence, Brie Larson and Jon Hamm are among the stars calling on fans to lobby U.S. politicians on behalf of women's health charity Planned Parenthood.

The Hollywood actors are among a host of famous names who appear in a new video released by the organization, which provides medical care and family planning for people in the U.S.

In their message, posted on media company NowThisHer's Facebook page, the stars urge the public to call their U.S. Senator to lobby them to vote against any legislation which would withdraw government funding from Planned Parenthood.

The video also features Lena Dunham, who also posted the message on her Lenny Letter website, feminist and activist Gloria Steinem, Star Wars actor Riz Ahmed, filmmaker Judd Apatow, The Handmaid's Tale star Elisabeth Moss, and funnywomen Amy Poehler and Aubrey Plaza.

The stars direct fans to sign up to Planned Parenthood's website istandwithpp.org in order to allow staff to connect them to their Senator's office.

Planned Parenthood's funding is currently under threat from the recently released Senate version of the American Health Care Act, which includes legislation barring individuals from going to the organization for preventative care.

In the video, the stars run through contact information and a script which accuses the bill of being "nothing more than a blatantly political attempt to do whatever it takes to attack women's health and rights and take health care away from the people who need it most".

Cecile Richards, president of Planned Parenthood Action Fund, said in a statement: "We are so grateful to have the support of so many artists, many of whom have themselves relied on Planned Parenthood for health care and who understand the importance of speaking out."

She added: "This support is especially important right now as the Senate is jamming through a bill that would block millions of women from getting birth control and cancer screenings at Planned Parenthood."

The controversial bill was unveiled by politicians from President Donald Trump's Republican Party on Thursday (22Jun17), ahead of being put to a vote in the Senate.

Other stars who appear in the video include Alison Brie, Phoebe Robinson, Constance Wu, Spike Jonze and Suki Waterhouse.