By Elaine Lies

TOKYO (Reuters) - The governor of Japan's capital, who is under fire for using tax money to pay for family vacations and art, faces demands to quit over a scandal that may affect national elections and embarrass Tokyo as host of the 2020 Summer Olympics.

Yoichi Masuzoe's predecessor had to quit over a funding scandal soon after Tokyo won the Olympics hosting rights and now lawmakers in the Tokyo assembly are calling for Masuzoe's head after repeated inability to justify his use of public funds, which included buying comic books for his children.

Masuzoe, 67, who won election in 2014 with support from Prime Minister Shinzo Abe's ruling coalition, will face more pressure to quit as lawmakers from Abe's ruling party Liberal Democratic Party (LDP) and the opposition prepared to submit a motion of no-confidence in him, which is expected to pass in the assembly on Wednesday.

But the timing is delicate, balancing coalition fears that Masuzoe could hurt them in a July 10 upper house election against the embarrassment of having a stand-in governor accept the Olympic flag at the Rio Olympics - a symbolic handover that passes the Olympics to the next host.

Masuzoe has asked for more time, pledging to return his salary but asking to postpone the no-confidence vote until after the Olympics end on Aug. 22, since losing the vote could mean a gubernatorial election during the Olympics.

"I don't intend to cling to the governor's seat," he told the Tokyo assembly after hours of questioning on Monday.

"But I think the confusion of having an election at the same time as the Rio Olympics would not be to the benefit of the next Olympic host city."

Masuzoe met an official of the ruling Liberal Democratic Party (LDP) party on Tuesday who pressed him to resign before the Wednesday vote, but he declined to do so, NHK national television said.

LDP officials have acknowledged that the scandal, which has brought a flood of complaints from voters, could make things tough for the party.

Tokyo 2020 Olympics planning officials said Masuzoe's woes were having no impact on preparations for the games, but planning has been hit by troubles including the scrapping of plans for the main stadium and plagiarism allegations forcing them to abandon their original games logo.

Tokyo's bid has also come under scrutiny after questions were raised about payments by the bid committee.

(Additional reporting by Kaori Kaneko; Editing by Nick Macfie, Robert Birsel)