negotiate the renewal of the union contract

Consider this scenario: it is time to negotiate the renewal of the union contract. The union leadership has asked for an increase of $2 an hour of wages and three more days of vacation for employees. Company leadership is arguing against any changes to the current contract in order to maintain competitiveness. The company has a hard-nosed positional bargainer.

You represent the union and seek to engage in interest-based negotiations. What techniques would you use to get the other side to engage in interest-based negotiations? What are the positions, interests, and BATNAs of each side?