Japan’s socialist party has voted to leave the ruling coalition because of a row over a US base in Okinawa.

The Social Democratic Party (SDP) had opposed PM Yukio Hatoyama’s decision not to move the US Futenma airbase off the southern Japanese island.

On Friday Mr Hatoyama fired SDP chief Mizuho Fukushima from her ministerial post over her stance on the issue.

The SDP has few seats in parliament but the coalition deal secured the ruling party a majority in the upper house.

The decision came at a meeting of senior party officials.