Evri said it was “surprised” that the GMB had recommended drivers reject a pay deal it developed with the union following discussions, amid threats of industrial action.

The GMB said more than 6,000 couriers had voted on the deal, with almost 97% turning it down.

The parcel delivery company said its offer came about through talks with the union and included rate protections and additional bonuses of up to £875.

Evri added that it also guaranteed all participating GMB Evri Plus members a minimum equivalent hourly rate of £14.10 plus expenses, which was above both the national living wage and recent pay offers from many UK businesses, including supermarkets.

However, the union recommended drivers turn it down: “This overwhelming majority sends a clear, united, and decisive message,” said Nicola Savage, GMB national officer.

“Evri couriers do a gruelling job, delivering millions of packages across the UK in a timely fashion, often getting nothing but abuse for their hard work

“It’s no wonder they are demanding a decent pay rise.

“This pay offer is a year late and is well below what they feel they deserve.”

Savage added: “GMB will now meet with Evri members to discuss next steps, which could involve industrial action.”

Evri said its proposed package had also included paid holiday, pension contributions, parental leave and support with fuel and vehicle costs.

“We consider this pay deal to be a fair and competitive package that reflects the vital role our community couriers play in our business,” said an Evri spokesperson.

“The offer was developed following discussions with the GMB and represents a significant multi-million pound investment from Evri in pay and benefits.

“We are disappointed that the ballot was delayed beyond our control and that GMB Evri Plus members were not given the opportunity to fully understand the details of the offer.

“Following constructive negotiations, we were surprised by the decision by GMB to recommend a no vote.

“We are continuing to engage with the GMB to better understand their position and to move discussions forward constructively.”