A group of US Senators has sent a letter to Nikki Haley, the country’s ambassador to the United Nations, urging her to work with other members of the UN Human Rights Council to pass a resolution on Cambodia’s political situation.

The bipartisan letter, dated Friday, alleged a “widespread attack” on political opposition, civil society and journalists, noting that Cambodia’s “fragile and burgeoning democracy” is in danger.

The letter was signed by Lindsey Graham, chairman of the State and Foreign Operations subcommittee, and two of his subcommittee colleagues. They were joined by Senator John McCain, a frequent critic of the Cambodian government, and four members of the Senate Committee on Foreign Relations, including ranking Democrat Ben Cardin.

In September, opposition leader Kem Sokha was arrested on widely decried charges of “treason”, with his party, the Cambodia National Rescue Party, subsequently dissolved in November.

“The crackdown has essentially ended the country’s nascent democratic system and cemented the rule of Prime Minister Hun Sen’s ruling Cambodian People’s Party,” the letter states, going on to claim the CPP both “led the crackdown” and controls the courts. “It is now clear that barring any seismic reversal in the government’s actions, the upcoming elections this year will not be free and fair.”

The senators said they welcomed the Trump administration’s decision to cut funding to Cambodia’s National Election Committee and to impose a visa ban on certain high-ranking government officials, though they expressed “concern” that the list is “still under review”.

They then called for more action to “isolate the Cambodian government” and pressure them to reverse course, going on to say the international community should not validate the “illegitimate ‘election’” in July.

The statement called on Haley to appeal to partners within the UN, and to bring up the issue during the upcoming Human Rights Council special session in February.

“We would urge you to work with other governments to pass a strong resolution that puts the government on notice on the international stage,” they wrote.

Phay Siphan, a spokesman for the government and a newly minted member of the CPP’s central committee, said he doubted criticism from the international community of the election’s legitimacy would negatively impact Cambodia.

“There’s no such law that gives a foreign nation [the right] to consider the government not legitimate,” he said.