A former Quebec construction union boss has pleaded not guilty to charges relating to the alleged fraud of tens of thousands of dollars in inflated expenses.

Jocelyn Dupuis appeared in a Montreal courtroom today and pleaded not guilty to fraud and fabricating fake documents.

Dupuis is the former head of the Quebec Federation of Labour's construction wing.

The charges relate to alleged offences between December 2007 and November 2008, a period in which Dupuis filed 43 expense accounts totalling $225,000.

The Crown's first witness was a union accountant who said Dupuis was the only employee to give him handwritten receipts because he didn't use a union-issue credit card.

Rolland Brillon testified that in one particular week Dupuis billed the union for $4,600 in restaurant meals, $1,800 in hotels and $510 for 1,400 kilometres worth of mileage without ever leaving the Montreal area.