Postal workers at Royal Mail Plc upped the ante in a confrontation with management over pay with a vote that rejects demands for restructuring and modernization and paves the way for further strikes.

Almost 99% of votes cast backed the triggering of a “formal dispute” over contracts and working conditions, providing a legal mandate for more walkouts beyond the four days already announced as part of a parallel action aimed at securing higher wages, the Communications Workers Union said Wednesday.

“In these times, working people need more security on the job, not less, and we won’t be backing down until we secure an acceptable solution,” CWU Deputy General Secretary Terry Pullinger said in a statement, pledging “fierce opposition” to attempts to “whittle away” existing rights.

The deepening of labor strife at Royal Mail comes as companies across Britain suffer a surge in industrial action as soaring inflation stokes pay claims while labor remains in short supply. From Thursday, rail workers will stage a series of nationwide strikes, as bus and subway staff walk off the job in London.

Shares of Royal Mail closed 0.3% lower and have lost 46% of their value this year as the company struggles to revamp its business to tap increased parcels demand and the surge in online shopping triggered by the Covid crisis eases.

Royal Mail has said it will sustain a full-year loss if 115,000 staff go ahead with strikes. The walkouts currently planned -- on Aug. 26 and 31 and Sept. 8 and 9 -- were announced after bosses imposed a 2% pay increase when UK inflation is forecast to exceed 13% later this year.

The company, which was privatized in 2013, has mooted plans to split the main UK postal business from a more profitable international logistics arm if unions continue to frustrate efforts to reorganize British operations that are losing £1 million ($1.2 million) a day.