Talks have begun aimed at averting this week's national postal strikes as union leaders confirmed they were considering legal action against the Royal Mail's plan to take on 30,000 temporary staff. The company said it was hiring twice as many temporary workers as normal to deal with the effects of the strike as well as the usual Christmas rush. The Communication Workers Union (CWU) said it believed the decision could be unlawful. Union officials held fresh talks with Royal Mail bosses with little sign of a breakthrough to a long-running dispute over pay, jobs and working conditions. Up to 120,000 union members will strike on Thursday and Friday, threatening massive disruption to mail deliveries just weeks from Christmas. Billy Hayes, general secretary of the CWU, attacked the Royal Mail's decision to hire so many temporary workers as "stupid" and warned that it would inflame the dispute.