Tokyo, May 30 (DPA) Japanese Prime Minister Yukio Hatoyama came under increased pressure Sunday as a party in his coalition government walked out, in the wake of a row over the relocation of a controversial US military base on a Japanese island.

The coalition had been in government since September.

The Social Democratic party (SDP) accused Hatoyama of breaking his election promise to move the US Marine Corps Air Station Futenma off the southern island of Okinawa.

Hatoyama had removed the SDP’s leader, Mizuho Fukushima, from her post as minister of consumer affairs because of the SDP’s opposition to the base.

The prime minister and his Democratic Party of Japan achieved a historic victory in elections at the end of August last year, ending half a century of conservative Liberal Democratic Party (LDP) rule.

Since then it has ruled in a coalition government with the SDP and the People’s New Party.

But a party fund-raising scandal and the reneging on the election promise over the base has seen him lose a lot of support.

According to a poll released on Sunday by the news agency Kyodo, support for the premier has sunk to 19.1 percent. Former ruling party the LDP could count on more support than his SDP.

Over half, 51.2 percent, of those questioned said that Hatoyama should resign because of his decision over Futenma.

Friday, the US and Japan had agreed to relocate the base to a less densely populated part of the island, the coastal region of Henoko, where there is already a US base.