Telus chief financial officer Robert McFarlane said that as of last week the company's common shares were up 5.5 per cent and its non-voting shares were up 7.2 per cent since the plan was announced in late February.
"The good part for our shareholders is that our share prices have gone up significantly greater than the market or our peers," he said, noting the Toronto Stock Exchange declined 3.1 per cent in that period.
"If it's voted down, those gains could reverse and so our shareholders could have a value destruction."
Telus shareholders will vote on the proposal to create a single class of common shares at the company's annual meeting on May 9 in Edmonton. Telus said a single class will provide better liquidity and benefit all shareholders.
However, Mason Capital Management has urged Telus shareholders to vote against creating the single class of shares. The U.S.-based investor said one class of common shares would hurt liquidity and reduce the allowed level of foreign investment.
"The imposition of burdensome foreign ownership procedures, and the risks to non-Canadian investors if foreign ownership problems arise, will further dampen liquidity," Mason Capital said in a letter to Telus shareholders.
"If the aggregate holdings by non-Canadians of voting and non-noting shares currently exceed 33 per cent, Telus will be required to force non-Canadians to sell their shares in order to implement the proposal."
The Telus plan to consolidate its shares requires approval by two-thirds of both its common and non-voting shareholders at the annual meeting. Mason already owns a fifth of the common shares and could get support from other shareholders.
Vancouver-based Telus said its plan would give each shareholder one vote for every one share they own and accuses Mason of trying to defeat the proposal for its own short-term profit.
Non-voting shares tend to trade at a discount to common shares, but after Telus disclosed its plan, both classes of stock started to align with each other in anticipation of the arrangement being a success.
McFarlane said Mason wants the spread between the two classes of shares to widen only to make money.
He said Mason owns 33 million voting shares, or 19 per cent, and shorted almost the same amount in non-voting shares, essentially betting the price of those shares will fall if the share consolidation plan is defeated.
"So why would someone go long and short in the same company? The answer is they've got a trading strategy that maximizes the gap between the two share classes. So they will benefit economically to the extent that gap widens," McFarlane said.
The spread was about four per cent, or $2.50, before the announcement, and had narrowed to between 40 cents to 50 cents, he said.
Canaccord Genuity analyst Dvai Ghose said one class of shares is in the interests of all Telus shareholders, noting Telus shares have gone up since the February proposal.
"In contrast, shares of Telus' nearest peer BCE are flat over the same period, suggesting that the proposed collapse has not impacted voting shareholders negatively," Ghose wrote in a recent research note.
Telus has said foreign ownership in its shares has never exceeded 20 per cent since U.S.-based telecom Verizon sold its last stake in the company in 2004.
Traditionally, the non-voting shares have been primarily held by Canadian institutional and retail investors.
Proxy advisory firm Glass, Lewis & Co. reiterated Monday its recommendation to institutional clients that they vote in favour of the plan to eliminate the dual class share structure.
On Friday, proxy advisory firm Institutional Shareholder Services reiterated its support for a single class of shares and recommended to its institutional clients that it support the proposal.