Prime Minister Hun Sen's government is expanding its efforts to muzzle speech as it prohibited a Cambodian-born Australian lawmaker from entering the country and escalated its legal war against its domestic political opponents. On Wednesday the Cambodian Ministry of Foreign Affairs classified Victoria lawmaker Hong Lim as persona non grata after he referred to the Hun Sen's government as a "savage regime." While the Australian Embassy in Phnom Penh defended Lim's freedom of speech, saying in a statement that "Australia has a robust tradition of different views being aired," it also pointed out that Lim is MP for the state of Victoria and "does not speak on behalf of the Australian Government." "We recognise the concerns this particular matter has raised," the embassy wrote in a statement. "Australia values its strong and enduring relationship with Cambodia and we look forward to this continuing." Australia and Cambodia have a deep diplomatic relationship that includes the large role Canberra played in the Cambodian peace process in the 1980s and the United Nations Transitional Authority in Cambodia in 1990s. Both countries work together to combat human smuggling trafficking, child sex tourism, narcotics trafficking and terrorism. In 2014 the two countries signed a controversial agreement allowing refugees from Australia to resettle in Cambodia. The deal was met with protests as Cambodians wondered how their country could afford to take care of the refugees when a rich country like Australia can't or won't. The deal was also widely condemned by human rights organizations and Antonio Guterres, the U.N. High Commissioner for Refugees at the time, called it a "worrying departure from international norms," adding that countries must not shift their refugee responsibilities among themselves. Australia agreed to supply Cambodia with $35 million in aid as part of the deal, but there are worries that most of the money would get siphoned off by corrupt officials before it reaches the refugees. Legal effort takes on domestic politicians While Hun Sen's government was busy keeping a foreign lawmaker critical of the regime out of the country, it is also ramping up legal pressure on domestic lawmakers critical of the regime. The Phnom Penh Municipal Court on Tuesday re-issued a summons for opposition party Senator Thak Lany, ordering her to appear before the court on August 17. She did not appear in court on August 8 in response to an earlier summons. Her attorney, Som Sokong, told RFA's Khmer Service that he will show up for the court hearing, but is unsure if Thak Lany will attend. Hun Sen has sued Thak Lany and Cambodia National Rescue Party (CNRP) leader Sam Rainsy for defamation over remarks they allegedly made that tie the July 10 murder of critic Kem Ley to the prime minister. Thak Lany denies she made the remarks, saying that her comments were edited to make her look like she was lodging the criticism. While Hun Sen hasn't been shy about bringing the force of the Cambodian legal system to bear on his opponents as a way to mute their criticisms, they often attempt to speak out when they can. "Constitutional coup' Jailed CNRP Lawmaker Um Sam An accused Hun Sen of staging a "constitutional coup" on Wednesday as he was being ushered to a prison vehicle following a supreme court hearing on his request for provisional release. "Hun Sen and his Cambodian People's Party (CPP) have staged a constitutional coup by putting me behind bars while I am protected by parliamentary immunity," he told reporters. "Ironically, he who fights to reclaim the ceded land is incarcerated while he who cedes the land is at large." Um Sam An was jailed after Hun Sen ordered police to arrest anyone accusing the government of using "fake" maps to cede national territory to neighboring Vietnam. The lawmaker says he found a map in the United States' Library of Congress that he claims is different from the one Hun Sen and the government used to represent the final say on the border issue. On April 12, the Phnom Penh Municipal Court officially charged Um Sam An with two criminal offenses over his accusations that the government had conceded land to Vietnam along its border. Um Sam An's counsel Hem Socheath told RFA that he has the right to speak his mind as an elected official with parliamentary immunity. Cambodian lawmakers have immunity from prosecution for opinions expressed in the exercise of their duties. A two-thirds vote of the legislature is necessary to strip a lawmaker of his immunity unless the legislator is caught in the act of committing a crime. "As an elected MP, my client enjoys his parliamentary immunity and freedom of expression. This right is guaranteed in the constitution," Jem Socheath said. "He did not commit an in flagrante delicto crime as accused. He was arrested in 2016 for a Facebook comment he made in 2015."