Thousands of women are expected to join a march in London later as part of an international campaign on the first full day of Donald Trump’s presidency.
The rally is among events in the UK and elsewhere planned in solidarity with the Women’s March in Washington, which is expected to draw a 200,000 crowd.
Organisers aim to highlight women’s rights, which they perceive to be under threat from the new US administration.
A protest against Mr Trump took place at the US embassy in London on Friday.
Singer Lily Allen joined demonstrators, local politicians and trades unionists outside the building in Grosvenor Square to highlight concerns raised by his election campaign on issues including nuclear weapons, climate change and immigration.
Other protests took place in Edinburgh, Glasgow and Manchester as Mr Trump was being sworn in as the 45th US president.
Saturday’s marchers say they will be voicing concerns over issues including racial and gender equality, affordable healthcare, abortion rights and voting rights.
Demonstrations in the UK are scheduled for Belfast, Cardiff, Lancaster, Leeds, Liverpool, Manchester, Shipley and Edinburgh.
The London march – which begins outside the US embassy and finishes at Trafalgar Square – has attracted celebrity support on social media from Sandi Toksvig, Alexa Chung, Charlotte Church, Pixie Geldof, Bianca Jagger, June Sarpong and Ian McKellen.
Almost 700 so-called “sister marches” are planned on Saturday across the globe. Protests by women have already taken place in Australia, New Zealand and Japan.
The largest demonstration so far has been in Sydney, Australia, where more than 3,000 protesters carrying placards with anti-Trump slogans took to the streets before gathering in the city’s Hyde Park.
Meanwhile, Prime Minister Theresa May has congratulated President Trump on taking office, saying “we are both committed to advancing the special relationship between our two countries and working together for the prosperity and security of people on both sides of the Atlantic”.
But in an interview with the Financial Times, the prime minister said she would have “very frank” talks with the new president on issues where their opinions appear to differ, such as Nato.
Foreign Secretary Boris Johnson said the UK will work “hand in glove” with Mr Trump’s administration “for the stability, the prosperity and the security of the world”.
But former Labour leader Ed Miliband tweeted: “Feared the reality of today would be worse than the anticipation and it is”.
Liberal Democrat leader Tim Farron said he missed watching the swearing-in ceremony, tweeting a picture of himself delivering campaign leaflets, and the message: “Apparently there’s something on telly, but I found something better to do instead…”