"Today in the special cabinet meeting the prime minister told us he will conduct a cabinet reshuffle," chief government spokesman Osamu Fujimura told reporters. "The resignations of all cabinet ministers were collected."

The reshuffle had been widely trailed in Japanese media, and comes as the prime minister's poll numbers remain dreary after a costly battle over legislation to double sales tax.

It also comes as Tokyo is embroiled in a row with Beijing over the sovereignty of a group of islands in the East China Sea, known as the Senkakus in Japan and the Diaoyus in China.

Newspapers have said Noda is expected to elevate Makiko Tanaka to the cabinet, a woman with pro-Beijing credentials reflecting her father's status as the prime minister who normalised ties with China in 1972.

Fujimura said the prime minister would meet senior leaders from his Democratic Party of Japan later in the day and hold a press conference shortly afterwards, at which his cabinet is expected to be revealed.