The next day she bolted from the country, joining half of the kingdom's opposition lawmakers in self-exile.
They have fled since September 3 when their party chief was arrested in the middle of the night by hundreds of officers, a dramatic escalation of a purge of rivals to Cambodia's strongman premier Hun Sen, one of the world's longest serving leaders.
"I don't intend to be captured," Mu Sochua told AFP from Bangkok, where she arrived on Tuesday and will stay before heading to Europe.
"I don't intend to sit and wait for a kangaroo court to give us a trial that is a total joke."
Her anxiety is well founded.
Through a mix of threats, harassment and legal entanglements, Hun Sen's government has been clearing out critics ahead of key elections that will test the premier's 32-year run.
And the odds are looking good for the 65-year-old, a master of manipulating the country's malleable democratic institutions in his favour.
The opposition Cambodia National Rescue Party (CNRP)is in tatters, with more than 20 MPs skipping abroad in the past month after their stand-in leader Kem Sokha was locked up in a remote prison on dubious treason charges.
His arrest comes months after a series of legal convictions and new laws forced the party's long-time frontman Sam Rainsy to step down.
Many civil society groups railing against corruption and repression have also been shut down or sidelined by court cases.
Outspoken media -- including the respected and recently shuttered Cambodia Daily -- have found the cost of criticism is a crippling tax bill.
- Repression the 'new normal' -
Deputy party leader Mu Sochua is no stranger to intimidation.
The 63-year-old is a veteran of an opposition movement that has spent most of its time dodging Hun Sen's machinations.
But the latest crackdown, she says, feels different.
"For the first time I felt unsafe. And politically speaking, this is the first time I felt we no longer have the possibility of a dialogue," Mu Sochua told AFP, adding that police have been following the movements of her party's members around the country.
"I didn't want another leader caught, another voice being silenced. That left me with one choice only, which is to leave."
Despite the roadblocks set up against it, the opposition Cambodian National Rescue Party (CNRP) faired well in recent elections, buoyed by growing frustration over graft and inequality.
But the recent exodus of MPs abroad is unprecedented and severely cramps the party's ability to mount an effective campaign in next year's poll.
At this rate, a boycott of next summer's national vote is on the table if Kem Sokha remains in jail and repression of the media and civil society continues, said Mu Sochua.
She and others in exile will now travel the West to whip up global pressure on Hun Sen and his cronies from abroad.
But whether Western democracies -- once a source of vital aid for the impoverished country -- can still wield influence over the premier is in question.
China has steadily pulled Hun Sen into its orbit in recent years by lavishing the leader with aid and investment free of pressure to safeguard human rights.
That has relieved the autocrat from needing to at least maintain the semblance of a functioning democracy and free press.
In the past, his crackdowns were often followed by spells of relative freedom to keep democratic donors on board.
But with Chinese cash flowing into the coffers, that let-up might never come.
"What's new in all this is the feeling of permanence," said Sebastian Strangio, an expert on Cambodian politics.
"It looks like the current repression is becoming Cambodia's new normal."
Published : October 06, 2017
By : Agence France-Presse