A “women’s march” against U.S. President Donald Trump drew thousands of protesters in London Saturday.

The event’s Facebook page states: “Send a bold message to [the] new administration on their first day in office, and to the world that women’s rights are human rights.”

The London march, from the U.S. Embassy to Trafalgar Square, was just one of almost 700 “sister marches” happening this Saturday across the globe, including in Australia, New Zealand and Japan.

The UK incarnation attracted celebrity support on social media from Sandi Toksvig, Alexa Chung, Charlotte Church, Pixie Geldof, Bianca Jagger, June Sarpong and Ian McKellen.

On their website, the organisers claim the “U.S. election proved a catalyst for a grassroots movement of women to assert the positive values that the politics of fear denies”.

“On January 21 2017, the first day of Donald Trump’s Presidency, women-led marches… will take place across the world”, they announced. “We, the organisers of the London march, call on people of all genders to march in London as part of an international day of action in solidarity.”

The march is backed dozens of prominent charities, lobby groups and trade unions, including; Amnesty International, Greenpeace, Oxfam, Women’s Equality Party, The Green Party, Syria Solidarity Campaign, Unite the Union, Solidarity with Refugees, and the National Union of Students.

The organisers’ “guiding principles” cover a broad and specific selection of issues, and four of the six authors are linked to the Black Lives Matter UK movement.

They cover education, “police brutality”, migration, left wing redistributive economic policy, prostitution, abortion, and foreign aid.

They claim, for example, to be “committed to disrupting the school-to-prison pipeline that prioritizes incarceration over education by systematically funneling our children—particularly children of color, queer and trans youth, foster care children, and girls—into the justice system.”

They also state: “We believe that every person and every community in our country has the right to clean water, clean air, and access to and enjoyment of public lands.”

Another “guiding principle” reads: “We believe in immigrant and refugee rights regardless of status or country of origin… Immigration reform must establish a roadmap to citizenship, and provide equal opportunities and workplace protections for all.”