Media playback is unsupported on your device Media caption Japanese businessman Seijiro Takeshita said the MP's protest had "definitely crossed the line"

A member of the Japanese parliament has been reprimanded for attempting to involve the emperor in politics.

Taro Yamamoto is to be barred from future events at the Imperial Palace after handing a letter to Emperor Akihito about the impact of the Fukushima nuclear disaster.

Such contact is taboo in Japan, where the emperor is seen as a figurehead with no political role.

Mr Yamamoto has expressed regret but rejected calls for his resignation.

Japanese television stations have aired footage of the newly elected member of the Upper House making his approach to the emperor at an annual autumn garden party at the palace.

He hands over a letter, drawing the emperor's attention to the impact on health of the Fukushima disaster, which led to the evacuation of 150,000 people from the area around the plant that was damaged by an earthquake and tsunami in 2011.

The letter was quickly taken by a member of the Imperial Household Agency, which later described the approach as inappropriate.

Strict protocol

It led to an outcry in a country where the emperor's role remains highly sensitive nearly 70 years after Emperor Akihito's father renounced his divine status at the end of World War Two.

The American occupation forces allowed him to remain in position but ensured the new constitution allowed no political role for the monarchy in post-war Japan.

The emperor's public appearances are tightly controlled and governed by strict protocol.

Some right-wing political groups, however, would like to see him assume a more political role, harking back to the days of Japan's imperial might in the first half of the 20th Century.

Taro Yamamoto is an actor and anti-nuclear campaigner, who was elected in July as an independent member of parliament.

He said he accepted that his behaviour had been inappropriate, but that he was frustrated by his efforts to realise his campaign promises on the environment.