The whistleblower in Japan's Olympus Corp scandal, former chief executive Michael Woodford, plans to meet ruling-party lawmakers in Tokyo this week as he lobbies for reforms to Japanese boardrooms, a source said on Monday.

Woodford, an Englishman who was sacked as Olympus CEO by the firm's board two months ago, arrives in Tokyo on Tuesday on a mission to persuade employees and investors that he is the right person to return to his old job and put the firm back on track.

The 92-year-old maker of cameras and endoscopes has been engulfed by one of the country's worst accounting frauds, a 13-year cover-up of investment losses which has revived calls for reforms to check the power of executives in Japanese boardrooms.

Woodford plans to meet the lawmakers, members of a panel on corporate governance reform within the ruling Democratic Party of Japan on Thursday, a day after a much-anticipated deadline for Olympus to iron out its accounts, said the source familiar with the ex-CEO's itinerary.

He may also meet opposition Liberal Democratic Party MPs who have set up their own taskforce to consider corporate governance reforms -- changes that are being resisted by the country's biggest business lobby.

Woodford was sacked by unanimous vote of the Olympus board in mid-October, even though it included three outside directors.

He has told Japanese magazine Bungei Shinju that if he regained his old job, he would push for a U.S.-style system of strong external directors.

But he faces a battle with current management to return to helm of the company. Its existing board plans to resign, though not before it picks its own slate of successors.

Olympus is preparing to file its July-September earnings by Wednesday, a necessary step for the disgraced firm to remain listed and to boost its chances of surviving as an independent firm. It has lost almost half its value since the scandal broke.

It plans to hold a briefing on Thursday to explain the results, after admitting to a $1.7 billion scheme to hide investment losses stretching back as far as 1998.

Olympus shares hit a six-week high on Monday after it reiterated its intention to meet the Wednesday deadline, closing up 7.79 percent at 1,300 yen.

Investors will be looking at the overall impact of accounting restatements on Olympus' balance sheet and whether this could put the company under pressure to raise fresh equity.

(Additional reporting by Isabel Reynolds and Mari Saito; Writing by Linda Sieg; Editing by Edwina Gibbs, Chris Gallagher and Mark Bendeich)