Prime Minister Hun Sen on Wednesday offered an open door to Prince Norodom Ranariddh to return to Cambodia for Pchum Ben, the festival honoring the dead.
"I want him to come for Pchum Ben," Hun Sen said in a public speech.
Prince Ranariddh has accepted the results of July's election and supported the quick formation of a new government, Hun Sen said.
"He's been easy on me, so I am easy on him," Hun Sen said.
The prince faces an 18-month prison sentence if he returns from self-imposed exile, but government spokesman Khieu Kanharith said Wednesday the courts would suspend his guilty verdict, on breach of trust charges.
Court officials could not be reached for comment Wednesday.
According to the law, Hun Sen must request a suspended sentence to King Norodom Sihamoni, said Long Phal, secretary of state for the Ministry of Justice.
Khieu Kanahirth said Hun Sen has not yet made such a request.
Prince Ranariddh could not be reached for comment.
Norodom Ranariddh Party spokesman Suth Dina said the prince will return to Cambodia at the end of September.
Hun Sen said he would give two National Assembly committee seats to members of the Norodom Ranariddh Party.