More than 1,000 workers at two Morrisons supermarket distribution centres are being balloted for industrial action in a dispute over pay increases.
A union said strikes by staff could begin as a result before Christmas.
A total of 1,100 workers, all members of the union Unite, were involved in the action, said a spokesman.
Unite said the distribution centres concerned were Northwich in Cheshire and Wakefield, West Yorkshire.
Both distribute food and goods to Morrisons supermarkets throughout the North west, Yorkshire and beyond.
The union said workers had received an 'entirely unacceptable pay offer'.
It said most workers had been offered a three per cent pay increase, but claimed the lowest paid had been offered just two per cent.
Unite general secretary Sharon Graham said in a statement: "Morrisons is a multi-million pound operation which has financially benefited from our members working throughout the pandemic. Workers will simply not accept a pay offer which is a real terms pay cut."
The union also claimed it wasn't invited to take part in a recent job evaluation process .
The two-week industrial action ballot opened today - Tuesday - and closes on November 30.
"If members vote for industrial action then strikes could begin by mid-December," added the union in a statement.
Morrisons said talks were continuing with the union.
A spokesperson told the Manchester Evening News: "We are still in formal negotiations and are due to meet with Unite again tomorrow - Wednesday."
