Pohiva Tu'ionetoa has been in Australia on medical leave for over three weeks and is not expected to return to Tonga until at least the end of the month.
Reports have been circulating around the kingdom and over the internet that Mr Tu'ionetoa had been dismissed for health reasons.
Mr Pohiva has denied the reports and Mr Tu'ionetoa has attributed them to what he calls "opposition forces".
"Those people that are from the opposition to the government, perhaps want to make a story that could cause some concern to the Democracy Party. The truth of the matter is that there is no such decision from the Prime Minister."
Pohiva Tu'ionetoa said he continued to have the support of the prime minister and vice versa.
He also reassured the public that he would be able to carry out his duties as finance minister, despite not having been in the country since the cabinet was formed.
During his last term as Prime Minister, 'Akilisi Pohiva went through three finance ministers, sacking the two previous post holders before Mr Tu'ionetoa.