(CNN) — More than 800 officials from the United States and Europe have signed a scathing criticism of Western policy towards Israel and Gaza, accusing their governments of possible complicity in war crimes.

In a statement obtained by CNN, the officials say there is a “plausible risk that our governments’ policies are contributing to grave violations of international humanitarian law, war crimes and even ethnic cleansing or genocide.”

They accuse their governments of failing to hold Israel to the same standards they apply to other countries and weakening their own “moral standing” in the world.

Among them are around 80 United States officials and diplomats, a source told CNN.

In an unprecedented display of coordinated dissent since Israel’s war against Hamas began nearly four months ago, the signatories call on their governments to “use all leverage” to secure a ceasefire and to stop saying that there is a “a strategic and defensible rationale behind the Israeli operation.”

The public letter, released Friday, comes a week after the International Court of Justice (ICJ) found South Africa’s claim that Israel is committing genocide in Gaza to be “plausible,” and ordered Israel to “take all measures” to limit the death and destruction caused by its military campaign, prevent and punish incitement to genocide, and ensure access to humanitarian aid.

The statement “shows the depths of concerns and outrage and just horror that all of us are witnessing,” a US official with more than 25 years’ experience, who signed the letter, told CNN on Friday.

“The talking points that keep being delivered day after day are not cutting it.”

The US official told CNN that the signatories were motivated by their shared experience of having their concerns be ignored by their governments and by “the appropriateness” of public dissent by civil servants when ignored internally.

The official added that the ICJ’s decision to hear a genocide case lodged against Israel was validation for the authors’ concerns. Israel has strenuously denied accusations of genocide in Gaza.

“What was really important for those of us on the US side was to link arms with the people in Europe who believe their governments are following the US lead, and feel constrained by that,” the official said. “So we thought it was important that US officials continue to make clear their concerns with government policy on this.”

The statement, which does not list its signatories, says that it was “coordinated” by civil servants in European Union institutions, The Netherlands, and the United States, and endorsed by civil servants in Belgium, Denmark, Finland, France, Germany, Italy, Spain, Sweden, Switzerland, and the United Kingdom.

Despite the letter not listing its authors, the US official told CNN many colleagues feared losing their jobs, and that the lower number of US signatories reflected stronger protections for official dissents in Europe.

CNN has asked the U.S. State Department, the European Union, and the Dutch Foreign Ministry for a response to the statement. CNN has also reached out to the Israeli government for a response.

A senior British civil servant told CNN of the letter: “We feel that politicians have responded to the evolving situation, evinced by the Foreign Secretary’s words this week.”

In the letter, the officials say that they raised concerns internally within their governments and institutions, but their professional concerns have often been overruled “by political and ideological considerations.”

“We are obliged to do everything in our power on behalf of our countries and ourselves to not be complicit in one of the worst human catastrophes of this century,” they write.

Israel’s policies, they argue, are counterproductive to its own national security goals.

“Israel’s military operations have disregarded all important counterterrorism expertise gained since 9/11; and that the operation has not contributed to Israel’s goal of defeating Hamas and instead has strengthened the appeal of Hamas, Hezbollah and other negative actors.”

They say that Western support for Israel has come “without real conditions or accountability.”

“Our governments’ current policies weaken their moral standing and undermine their ability to stand up for freedom, justice, and human rights globally and weaken our efforts to rally international support for Ukraine and to counter malign actions by Russia, China and Iran,” they say.

Finally, they call on their governments to “develop a strategy for lasting peace that includes a secure Palestinian state and guarantees for Israel’s security, so that an attack like 7 October and an offensive on Gaza never happen again.”