Japan opposition making final preparations to submit no-confidence vote on Friday

TOKYO (Reuters) -Japan's opposition is making final preparations to submit a no-confidence vote against the government of Prime Minister Fumio Kishida, NTV reported on Thursday, which could trigger the dissolution of parliament and a snap election.

Speculation that Kishida would call an election intensified when his public approval ratings rose after he hosted the Group of Seven (G7) summit in Hiroshima, his home base, and a recent opinion poll showed his support still holding mostly solid.

The sustained strength of Japanese stocks, with the Nikkei share average on Wednesday hitting its highest level since March 1990, has also bolstered his standing.

But criticism of his government has risen over national identification card issues and furore over a party thrown by his son and former political secretary at the prime minister's official residence. Both situations prompted some ruling party policymakers to call for caution about an election soon.

Kishida told a news conference on Tuesday that he would decide whether to call a snap election based on a comprehensive review of various factors, without specifying what those were.

Several Japanese opposition groups, led by the main opposition Constitutional Democratic Party of Japan, are preparing to submit a vote of no-confidence opposing a bill to boost Japan's defence capabilities. The defence legislation is expected to come to a vote in the upper house of parliament on Friday.

Japan is struggling to secure funding for planned defence spending of 43 trillion yen ($309 billion) over the next five years and a plan to raise key taxes to do so has run into trouble amid wrangling among lawmakers.

(Reporting by Elaine Lies; Editing by Tom Hogue and Gerry Doyle)