Lesotho lawmakers and South African mediators said on Saturday that legislation awaiting assent from the king will see Prime Minister Thabane, suspected of killing his ex-wife, leave office soon, ending a crisis that has engulfed the mountain kingdom for months.

Thabane, 80, has been under pressure to resign over a murder case in which he and his current wife are suspected of assassinating his previous wife. The case has divided his party and triggered sporadic unrest. They both deny the charges.

"We are satisfied that when the king has assented to this bill, it will pave the way for the prime minister to indicate his intention to vacate the office,” South African envoy Jeff Radebe told journalists.

"As soon as His Majesty has assented to this bill the prime minister will indicate his intention to leave the office,”he added, without saying whether or not he had agreed to do so.

Thabane's spokesman did not immediately respond to a request for comment.

Thabane was quoted in media last week as saying he will not be hurried out of office, despite pressure from within his own All Besotho Convention Party, its coalition partners, opposition and regionally powerful neighbour, South Africa.

Political instability frequently boils over in Lesotho, which has experienced several coups since gaining independence from Britain in 1966. Its conflicts often draw in South Africa, whose central mountains encircle it. Perched at high altitude, Lesotho supplies vital drinking water to its drier neighbour.

Thabane has previously said he will leave at the end of July, but his opponents say that is not soon enough.

On Tuesday, the Senate passed a bill that prevents Thabane from dissolving parliament and calling fresh elections in the event of a vote of no confidence against him, meaning that should such a vote pass he has no choice but to leave.

"Now that the amendment has been passed, we are just waiting for it to be passed on to His Majesty for assent and there will be preparations for the PM to leave in a decent, dignified manner," ABC Secretary Lebohang Hlaele told Reuters.

Deputy leader of the opposition Democratic Congress, Motlalentoa Letsosa, said he was preparing a vote of no confidence that could go to parliament as early as next week if the king signs off on the amendment.

Independent political analyst Lefu Thaela said Thabane would most likely lose the vote, and would have a choice between stepping down and“going the dictatorship route”of digging in and hoping the military supports him.

Gunmen shot and killed Thabane's previous wife, Lipolelo, 58, on June 14, 2017, in a case that was never solved.

This year, police charged Thabane's current wife, Maesaiah, with the murder, and also named Thabane himself – though he has yet to be formally charged in court.