Like a weary wrestler rising from the canvas at the end of a long bout, Nathan Tinkler seems determined to prove he still has some financial muscle to flex.

Tinkler has hit the board of Whitehaven Coal — a company in which he owns a 19.4% stake worth about $635 million — with a letter demanding they provide him with a detailed update on operational and financial matters by close of business tomorrow.

Never mind that Whitehaven is due to provide the market with an update on Friday. He wants the information now and if he doesn’t get it he says he will use his stake to vote against the re-election of former Howard government trade minister and Whitehaven chairman Mark Vaile and four other directors at the company’s annual general meeting on November 1.

Whitehaven has this morning entered a trading halt following receipt of the letter.

Tinkler — who launched a spectacularly unsuccessful attempt to buy Whitehaven Coal for $5.3 million just months ago — wants to know Whitehaven’s own internal forecasts for earnings before interest, tax, depreciation and amortisation for 2012-13 are not “materially different” from the $180 million consensus forecast that analysts have. He also wants to know whether Whitehaven met its target of EBIDTA greater than $20 million in the September quarter and whether it managed to meet its target of producing more than 350,000 tonnes of coal from its Narrabri mine in the three months ended September.

Why Tinkler can’t wait an extra day to receive this information with all Whitehaven shareholders isn’t clear, but it suggests the move is more about Tinkler reminding Whitehaven and the rest of the world that he’s not the spent force everyone thinks he is.

Tinkler isn’t afraid to roll a board of directors and get in and make changes. He forced Vaile out as chairman of Aston Resources (a company in which he owned a majority stake) in November last year and also forced two directors out of coal junior Coalworks because he was unhappy with its performance.

Tinkler isn’t saying what his ultimate aim is here, but one theory is if he can prove the current board is not performing he will be able to get other shareholders to support his push for change. If he can seize control of the Whitehaven board, this theory goes, he could look to sell assets, increase dividends or even look to shop the company around.

Whether Whitehaven shareholders will support him so soon after his abandoned takeover bid is one question; whether his other financial issues reduce his ability to pull off a big corporate move like this is another.

While he appears to be on the edge of settling a $17 million fight with property developer Mirvac over a land sale, he still is yet to fulfil an agreement to inject $29 million into coal upstart Blackwood Corporation. On top of this, a 7.30 report last night made it clear he has a string of small debts around Newcastle, with creditors getting angrier by the day.

But Tinkler’s stake in Whitehaven remains the ace in his pack. And he seems determined to use it to make some sort of play.

*This article was originally published at SmartCompany