Lauris Klevin, with the International Brotherhood of Electrical Workers, says contract negotiations with Manitoba Hydro have reached an impasse. (CBC)

Thousands of Manitoba Hydro workers could be headed for the picket lines in what could be the utility's first strike in history.

The three unions representing some 4,600 hydro workers say a strike could happen by the end of the month.

"Oh, we're very serious," said Lauris Kleven, business manager with the International Brotherhood of Electrical Workers, which represents about 3,000 workers.

Another 1,300 workers are represented by the Canadian Union of Public Employees and 300 by the Communications, Energy and Paperworkers Union of Canada.

Contracts between Hydro and all three unions have expired. The agreement with the IBEW expired in April.

Kleven said negotiations have reached an impasse, primarily over salaries.

"We take pride in our work and we feel that we're deserving a fair salary increase at this point," Kleven said.

Other Crown workers given more

He said Hydro's current wage offer isn't fair when compared to other Crown corporations. The utility is offering a two per cent increase in the first year and essentially no increase in the second year, Kleven said.

In comparison, Manitoba Public Insurance just settled a four-year year deal with its workers that will pay a 2.9 per cent increase in each of those years, Kleven said.

A Hydro spokesperson said the utility is still hoping to resolve the dispute and avoid a strike, which would include electrical workers, truck drivers, transmission techs, clerical and customer service workers.

In an e-mail to CBC News, Glenn Schneider of Hydro said the following:

• Negotiations with Hydro unions are continuing and Hydro is not prepared to discuss details
• Strikes are always a possibility when negotiating a new contract
• We are making plans to do what we can to maintain service if a strike were to occur
• We continue to talk and expect to be able to reach an agreement

Ballots have been mailed to the workers this week, asking them to choose to accept the utility's current offer or provide the unions with a strike mandate.