The leader of Tonga's Friendly Islands Democratic Party, Akilisi Pohiva, says he is shocked that the Princess Regent and the Chinese Ambassador are publicly assisting the campaign of a candidate for next week's historic elections.
Mr Pohiva says on Monday night, Princess Pilolevu and the ambassador, Wang Donghua, attended the campaign meeting of Saia Moehau in the Tongatapu Number 6 seat.
Princess Pilolevu is understood to have had close business links with Mr Moehau.
Mr Pohiva says it's inappropriate for the Royal Family to be involved in the election process.
He says he's also concerned that the Chinese Ambassador attended the campaign meeting and promised aid to the electorate.
"They should get away from the campaign. They must not be seen taking sides or supporting a particular candidate. It's not good for the image of His Majesty and also for the Royal Family."
The leader of the Friendly Islands Democratic Party, Akilisi Pohiva
