Liberal Democrats councillor James Brown said at a meeting on Tuesday: “For that amount, we could have put on two Christmas markets.”
But Labour councillor Joshua Wells, the authority’s portfolio holder for inclusive economic growth, defended the market’s performance.
He said: “We have lost traders for a variety of reasons. Some have moved to independent premises or moved online.
“Since the business case was first put in, there have been economic shocks and the ongoing effect of the pandemic which has changed shopping habits.”
Wells highlighted the Teenage Market, the Festival of History and youth pop-up The Zone as efforts to bring people into the area.
“There is not a simple fix. Markets up and down the country are facing similar or worse situations,” he added.
Five retail stores and one food venue have applied for space at the market, councillors were told.