LONDON, Ont. -- London, Ont., Mayor Joe Fontana says it was "stupid" of him and a "mistake" to alter a document he submitted for expenses while he was an MP.

Fontana took the stand today in his own defence after pleading not guilty to fraud, breach of trust and uttering forged documents from his time as a Liberal cabinet minister.

He says he altered an invoice for his son's June 2005 wedding to reflect the details of a reception he planned for then-finance minister Ralph Goodale at the same venue.

Even though that event did not happen as scheduled, Fontana says he believed he owed the Marconi Club a $1,700 deposit, but did not have any paperwork because he had only discussed the reception over the phone with the club's president.

A $1,700 Government of Canada cheque was ultimately sent to the Marconi Club, where it was listed on their books as payment for Fontana's son's wedding.

Fontana is objecting to the Crown's use of the word "forged," saying instead that he "changed" the invoice or "created a new document," believing the paperwork for his son's wedding deposit was at that point null and void.

"I was busy, it was available," Fontana said of the document that he altered. "Things were harried at the time in Ottawa -- a minority government."