Amazon workers at Coventry's warehouse are set to strike on Black Friday, in addition to three more days next month, in a dispute over pay.
The GMB union has confirmed members will walk out on November 7, 8 and 9 as well as on November 24 - one of the busiest days of the year for retailers.
The union said it will be the biggest day of strike action in Amazon's history, involving more than 1,000 workers.
This comes as Amazon UK announced yesterday it would be spending £170million on two pay rises for frontline staff over the next six months.
Earlier this year, 600 members walked out of the warehouse and embarked on a three-day strike. Members were asking for a pay rise from £10.50 to £15 an hour, but the union is not recognised by the US firm.
Rachel Fagan, GMB organiser, said: 'These strike dates will bring total days lost to industrial action to nearly 30.
'This is an unprecedented and historic moment with low-paid workers taking on one of the world's most powerful corporations.
'This is our members' response to the failure of Amazon bosses to listen.
'Coventry is the beating heart of Amazon's distribution network. Strike action here on Black Friday will ripple throughout the company's UK logistics.
'As Black Friday looms, Amazon must urgently reconsider their priorities or risk strike action causing widespread disruption to customers and the public.'
Yesterday's announcement stated that from October 15, the minimum starting salary would increase by at least one pound an hour to between £11.80 and £12.50, depending on location.
Employees could also see the increase for all full-time, part-time, temporary and seasonal roles increase further next April to between £12.30 and £13 an hour, depending on location.
Regional Organiser for GMB Stuart Perry (right) tweeted: 'Another amazing day had on the picket line outside Amazon Coventry'. Pictured in April
In response to the internet giant's announcement yesterday, Rachel Fagan, GMB Organiser, said: 'This news will bring little comfort to the thousands of Amazon workers facing poverty pay, unsafe working conditions and workplace surveillance.
'Amazon has spent millions fighting their own workers over union rights and fair pay.
'GMB members have forced a pay rise from one of the world's most powerful corporations - but Amazon can and must do better.'
Amazon employs 75,000 people in the UK.
In April, more than 100 union members were believed to have joined the picket line outside the Amazon warehouse in Coventry.
A five-day strike was also staged by defiant employees in March - the industrial action was estimated to cost Amazon more than £2million.
Workers with GMB Union previously walked out on February 28 and March 2 after voting to strike in an industrial ballot last December.
Coventry workers also became the first ever UK employees of the online giant to take strike action on January 25, earning praise from Labour's Coventry South MP Zarah Sultana who said they were 'making history'.
