Campaigners seeking fair pay for Amazon workers claim the online retailer is now set to miss out on sales worth more than £2.5m this festive season after over 11,000 people signed a pledge to enjoy an “Amazon-free” Christmas.

Amazon Anonymous, which says that Amazon avoids tax, “don’t pay their workers a living wage … They take money away from our local shops”, launched the latest salvo in its campaign against the retailer on 18 November, calling on supporters to buy their Christmas presents elsewhere. By the morning of Cyber Monday, 11,463 people had pledged “to avoid shopping on Amazon from 1 to 25 December”, promising to spend a combined total of £2.59m at other retailers.

“We are staggered by the response and support we’ve received from the public and soon-to-be ex-Amazon customers, as well as smaller retailers who are often undercut by Amazon’s aggressive business model. I didn’t expect it would be this big after just two weeks. I think we can double the current figure over the next few weeks as we get closer to Christmas,” said Bex Hay, co-founder of Amazon Anonymous.

The campaigners acknowledge that “going cold turkey is hard”, and have worked with Ethical Consumer magazine to provide a guide to alternative retailers for those pledging to boycott Amazon. It ranges from independent booksellers – “Local independent book stores have been at the centre of our communities for over a century but now, thanks to the tax avoidance antics of Amazon, they are a dying breed. They are usually family run and have a very small turnover so your custom will make a big difference” – to Oxfam.

“We’ll be providing plenty of support and tips on how best to avoid Amazon, to maximise the impact and help everyone stick to their pledge. The Amazon-Free shopping guide is a first step to get through Cyber Monday unscathed,” said Hay.

Tim Hunt at Ethical Consumer said the organisation had been running its own boycott of Amazon for two years. “Amazon’s aggressive tax avoidance is doing untold damage to our high streets and their offshore shenanigans keep their UK tax payments obscenely low. In these times of austerity it is vital that corporations pay their fair share of tax, sadly it seems that Amazon are not currently doing this.”

Amazon’s payment of £4.2m in tax last year, on sales worth £4.3bn, was attacked by Margaret Hodge, chair of the public accounts committee, in May. Amazon has said that it “pays all applicable taxes in every jurisdiction that it operates within”.

Amazon Anonymous was launched last Christmas by a group of Amazon shoppers “disgruntled” that the retailer “does not pay a living wage to warehouse workers”. At the time the Living Wage was set at £7.65 an hour outside London. Amazon.co.uk says on its website that: “In the UK, permanent associates start on an average of £7.39 per hour and earn up to £8.90 per hour after 24 months.”

The campaigners previously gathered more than 65,000 signatures to a petition calling on the retailer to pay its workers the living wage, and to treat them better, slamming what it says is Amazon’s “sack-if-you’re-sick policy that sees you turfed out if you take three sick breaks in a three-month period”, “giving workers 15-minute breaks that start wherever they are in the giant warehouses”, and “a ‘performance console’ that tracks and logs workers’ activities so they can be released if their ‘pick rate’ is too slow”.

The campaigners collected testimonies from Amazon workers online, and delivered the petition to Amazon in February, but were unsatisfied with its response: “Their reply explains the wage rates paid to Amazon’s permanent staff, but sidesteps the small matter of tens of thousands of temporary contract workers on poverty wages,” they said at the time. They followed up by asking supporters to email Amazon directly registering their disappointment with the response, and asking it to “raise its baseline pay for permanent associates from £7.10/hour to the living wage rate of £7.65/hour”.

Amazon did not respond to a request for comment.

“We are sending a strong message to Amazon, during their busiest time of the year, that if they don’t make a proper contribution to our society, we won’t give them our money,” said Hay.

Kivin Varghese, a former Amazon employee who is embroiled in a long-running legal dispute with the internet retailer and is currently on the sixth day of a hunger strike outside Amazon’s Seattle headquarters over its business practices and treatment of employees, added his voice to Hay’s. “I’m calling on customers to join us in protest: don’t give your money to Amazon this holiday season - that’s the best way we can drive change,” said Varghese. “It’s time Amazon faced up to the human toll of its long-standing unethical and draconian business practices.”