TOKYO - PUBLIC support for Japan's Prime Minister Taro Aso has plunged below 20 per cent as his party faces losing its grip on power in upcoming elections, a poll showed on Saturday.

The rating of 19.7 per cent was down from 22.9 per cent in June and is the third consecutive decline, the Yomiuri Shimbun said in its latest snapshot of voter sentiment.

On Wednesday, Mr Aso named two new cabinet ministers as he explores ways to improve his sagging popularity ahead of elections which he must call by September.

But the poll showed 56 per cent of respondents did not support the move, which was backed by just 16 per cent of those questioned.

Twenty-four per cent said they wanted Mr Aso to stay in power following the elections, while 41 per cent said they wanted opposition leader Mr Yukio Hatoyama as prime minister.

Mr Aso's Liberal Democratic Party has been out of office only once since 1955, when a coalition of several opposition groups took power for just 10 months in 1993-94.

The daily carried out the survey on Thursday and Friday, questioning 1,021 eligible voters across the nation. -- AFP