Orchestra London is on the brink of financial ruin.

Just months after projecting a $50,000 surplus, news of the shortfall is sending resounding shock waves through concert halls and city hall.

Ultimately, taxpayers would be on the hook for $500,00 of the organization's debt.

Even as last ditch efforts are being made by executive director Joe Swan to find a financial bail out, new questions are emerging about how much information city hall had about the financial slide experienced by the orchestra.

Wednesday night's performance by Orchestra London is looking more and more likely to be its final note according to deputy mayor Paul Hubert.

"I think the end of the orchestra is coming really to a crashing halt."

Hubert says he is unlikely to support a request next week from the orchestra to advance at least half of its annual $500,000 municipal grant.

Swan was in Toronto Thursday, telling CTV News in a text message that efforts to save the organization continue.

"All sources are being pursued no stone unturned," Swan's messaged stated.

Hubert says he's disappointed that city hall was only made aware of the financial crisis this week and not earlier.

"We've been asking for literally months for the orchestra's financial statement. Their year end was June and they are supposed to be giving us monthly financial updates and we haven't' had them since sometime last spring," says Hubert.

If Orchestra London does go bankrupt, city taxpayers will have to pick up a sizable portion of its debt.

Documents from a line of credit renewal just this past September show a figure for $500,000.

If the orchestra can't pay it back, city hall has guaranteed that it will, though that decision was based in part on incomplete information.

At the time, Orchestra London suggested its June 2014 year end financials indicated a draft surplus of $46,820 although the figures had not been audited.

The accounting firm conducting the audit said preliminarily, "Nothing material has come to our attention to date as a result of our field work that would require adjustment from preliminary internally prepared figures provided to you by the organization."

Months later, the audited financial report has yet to be released.

It's uncertain if city staff were told that Orchestra London was still trying to meet conditions to receive the $350,000 donation which ultimately never came.

Hubert says if orchestral music returns to London, he would demand fundamental changes at the top.

"I would certainly be looking for a whole new business plan and a whole new leadership structure that would lead them forward," says Hubert.

Two shows had to be cancelled this weekend because of financial shortfalls.