Celebrities including Bill Nighy and Paloma Faith have signed an open letter to the Foreign Secretary calling for further action to stop the “terrible” war in Sudan that has now raged for a year.

Actors Brian Cox, Alan Cumming, Bill Nighy and Will Poulter signed the letter to Lord David Cameron along with singers Annie Lennox, Paloma Faith and Peter Gabriel.

Film producer Barbara Broccoli, writer Candice Carty-Williams and historian and broadcaster David Olusoga also signed the letter.

Monday marks the first anniversary of the Sudan war that started when clashes erupted in the capital, Khartoum, between rival forces – the country’s military, led by General Abdel Fattah Burhan, and the Rapid Support Forces (RSF) paramilitary faction, commanded by General Mohammed Hamdan Dagalo.

At least 8.2 million people have been displaced inside and outside Sudan since fighting broke out on April 15 2023, the United Nations (UN) Office for the Co-ordination of Humanitarian Affairs reported.

But the letter signed by well-known creatives states: “For too long, this terrible war has gone on virtually forgotten. Enough is enough.”

The Circle, a “global feminist” NGO (non-governmental organisation) founded by former Eurythmics singer Lennox, gathered the celebrity signatories.

Lennox said: “We cannot sit back and watch this devastation unfold on our global sisters and innocent families. One year on is one year too long.

“Sudanese women and children need action to be taken now.”

The letter, also signed by grassroots organisations cross the globe, states: “Women and girls in Sudan must not be forgotten. The time to act is now.

“The Sudanese people are facing catastrophe. Since deadly fighting between two generals broke out in April last year, Sudanese civilians, and especially women and children, have been paying the price.

“Two decades after ethnic cleansing in Darfur, there is again credible evidence of mass killings by the Rapid Support Forces.

“And as the RSF appear to be winning more battles, the risk of genocidal violence spreading is growing.

“As ever, women are bearing the brunt of this conflict. Sexual and gender-based violence is widespread and being perpetrated by all parties to the conflict.

“We are calling on the UK government – and other key states – to put meaningful pressure on the warring parties, and the states that are sponsoring them – to stop the war.

“Violations of arms embargoes should have immediate consequences and sanctions should be applied against key individuals on both sides.”

From April 2023 to mid-December at least 118 people in Sudan suffered sexual violence including rape, gang rape and attempted rape, the UN High Commissioner for Human Rights reported .

It added that the numbers included 19 children.

The research released in February this year said Rapid Support Forces (RSF) committed “many” of the rapes, on streets and in homes, and one woman died after she was repeatedly gang raped over 35 days.

Only four victims of sexual violence were “willing and able” to report it to authorities “owing to stigma, distrust of the justice system, the collapse of the institutions of justice and fear of reprisals”, it added.

The Circle has funded South Sudan-based NGO, Root of Generations, set up by a woman who was displaced as a child by war in the region.

Its founder, Grace Dorong, said: “(I) ended up in a refugee camp in Kenya alone when I was between five and seven years old – I know the impact of losing your home and being in fear.

“Women and children are especially at risk in times of conflict; the desperation and violence women are facing including to their children is beyond imagining.”

Her organisation supports vulnerable households, seeks to end violence against women and girls, and now assists people who have escaped the crisis to displacement camps in Juba, the capital of South Sudan.

She said her organisation “shouldn’t need to be doing this” and that “decision-makers and leaders should see the women and children in the mirror when they look at themselves.”