Delivery giant Yodel now faces and employment tribunal while in the midst of a strike ballot that could bring the entire network to a standstill.
A total of 19 claimants have launched proceedings against Yodel over underpaid night shift work – with another 137 workers thought to be affected.
The hearing take place at the Employment Tribunal in London during October.
Meanwhile more than 250 Heavy Goods Vehicle (HGV) drivers will vote on whether to take industrial action over pay and conditions.
The strike ballot closes on September 15 – meaning industrial action could take place during Yodel's busiest 'peak' period in the lead up to Christmas.
The drivers are angry over their work life balance, the fact agency workers are paid more than directly employed drivers, annual leave payments that remain outstanding, a failure to offer substantial pay enhancements to stem the tide of drivers leaving the business for better paid jobs elsewhere and a failure to honour contractual agreements around pay for holiday and sick leave.
Steve Garelick, GMB Organiser, said:
“Yodel attempts to avoid obligations and agreements while claiming financial instability show an incredible amount of chutzpah - just weeks ago Yodel was announcing record profits.
“When HGV drivers see hourly rates as high as £40 per hour on a weekend and their pay starts at just over £13 they are bound to be angry.
“It’s no wonder they face strike action and tribunal given failures with management and HR to act in a collegiate fashion.
“If Yodel wants to fix this before their whole network breaks down they need to get back round the table with GMB as a matter of urgency.”