Tonga's acting prime minister, Dr Fred Sevele, says his appointment shows that the political reform process is continuing.
He is the first M.P. elected by the people to be appointed to the position upon its vacancy, although other commoners have previously held the post but not any who were popularly elected.
Dr Sevele says he doesn't know if, or when, he'll be confirmed in the post because that's a decision taken by the king.
But, he says there's been a slow process of change in the kingdom and this is another step in that direction.
Dr Sevele says he expects changes to continue but they won't be achieved overnight.
"I have made my views known and I've always said that change is inevitable and that people will have more say in the running of government. And, I have no reason to change my stance on that, and the recent events confirm, I think, that political changes are moving forward."
