Thabane is facing charges that he connived with his current wife, Maesaiah, to murder his then wife Lipolelo, in June 2017.
Thabane is suspected of involvement in the murder of Lipolelo who was shot dead two days before he took office for a second stint as premier, and two months before he married Maesaiah.
His lawyers challenged the court’s jurisdiction on Monday, arguing that as a serving premier Thabane was immune from prosecution.
The presiding magistrate referred the case to the High Court, which will be sitting as the Constitutional Court to decide on the application by Thabane’s lawyers.
Maesaiah Thabane has also been charged with the murder, with the prosecution arguing that she ordered the assassination.
Both deny any involvement.
The prime minister, 80, has already announced plans to step down in July, citing “loss of energy” to continue in the position.