(Adds comments from union and company Twitter)
TORONTO, Feb 20 (Reuters) - Canadian National Railway Co said on Friday that barring a settlement by this weekend with Unifor, a union that represents 4,800 of its mechanical, clerical and intermodal staff, it plans to begin to lock out employees on Monday.
In a post on its official Twitter account, the union called for CN Rail to "get back to the bargaining table," while the company responded on the social media platform by urging "union leadership to sit down & negotiate a deal this weekend."
Protracted contract talks between CN Rail and Unifor are at an impasse, and the union said on Thursday it planned to proceed with a vote to strike.
Unifor made the decision after CN on Wednesday said it would unilaterally alter a labor pact covering staff represented by Unifor if a new accord was not agreed by Feb. 20.
The union has balked at a government-mandated arbitration process, saying it would not accept government interference in its contract talks with the country's No. 1 railroad operator.
"We cannot accept the uncertainty that Unifor's month-long strike mandate process will create for our customers," CN Chief Executive Claude Mongeau said in a statement.
CN said it will exercise its right under the Canada Labour Code to lock out Unifor members effective 11 p.m. EST on Monday, Feb. 23.
The company also said it would deploy its labor disruption contingency plan, with trained management personnel performing the work of Unifor members, in order to protect service to its customers to the best of our ability. (Reporting by Euan Rocha, editing by G Crosse, Bernard Orr)