Bosses at Royal Mail are seeking an injunction to block a planned strike by postal workers, claiming there are “potential irregularities in the ballot” making the vote unlawful.
The company will go to the High Court on Friday for an interim order against the Communication Workers Union, whose members voted overwhelmingly for walkouts.
Royal Mail said: “The company is making this High Court application because the integrity and legal soundness of any electoral process is vital.
“This is particularly the case in relation to potential industrial action around the General Election on 12 December 2019. Royal Mail is also making this application because of the damage industrial action would do to the company and its customers in the run-up to Christmas.”
The dispute between workers and managements stems from a dispute over job security and employment terms and conditions.
Last month members of the CWU backed action by 97% in a turnout of almost 75%.
But Royal Mail said: “The company believes the evidence demonstrates that CWU officials, including co-ordination and direction at a senior level, have planned and orchestrated breaches of their legal obligations.”
It added bosses have found “at least 72” UK sites where staff were being asked to intercept and remove their ballot papers from mail coming into their delivery offices, before they were delivered to their homes.
The company added it had evidence of workers “being instructed to vote “yes” and being encouraged to do so in groups; and being encouraged to open their ballot papers on site, mark them as “yes”, with their colleagues present and filming or photographing them doing so, before posting their ballots together at their workplace postboxes.”
Royal Mail’s procedures state employees cannot open their mail at delivery offices without the prior authorisation of their manager.
Industrial relations at the company have worsened this year, with widespread unofficial strikes breaking out virtually every week.
The CWU previously said the result of the ballot, which was open between September 24 and October 15, represents the largest yes vote for national industrial action since the passing of the Trade union Act 2016.
Unions claimed up to 50,000 jobs were at risk at Royal Mail, as well as at Parcelforce under plans to separate it from the postal business.