Tongan voters will shortly find out who their new prime minister will be, with nominations closing today.
There are two candidates for the MPs to vote on, possibly later this week.
Our correspondent Kalafi Moala said in the past 24 hours the chances of caretake education minister, Siaosi Sovaleni, appear to have firmed.
He said Mr Sovaleni has gained support at the expense of his rival, former finance minister, 'Aisake Eke.
Aisake Eke Photo: RNZI/ Koro Vaka'uta
Mr Moala said Mr Sovaleni now has 12 MPs backing him with Mr Eke's numbers slipping to five, but he says the way the nine nobles vote remains the key.
He said there are reports that two nobles are preparing to back Mr Sovaleni, which give him the crucial 14 votes.
"So it looks absolutely unlikely that the nobles will stand together in their vote for Eke, particularly when you see such a gap in numbers," he said.
"For them to vote for Eke would show that they are really manipulating the choice for prime ministership, they are not going with the popular vote. They have their agenda."
Tonga's Prime Minister Hu'akavameiliku Photo: RNZI/ Koro Vaka'uta
