As Amazon's Black Friday sales are set to soar, furious staff will protest outside UK warehouses over what staff have called 'inhumane conditions'.

Insiders at the GMB Union have said protests in Rugeley, Milton Keynes, Warrington, Peterborough and Swansea could clash with the shopping surge at the end of this week.

Sources told BuzzFeed News staff have been 'knocked unconscious' and suffered broken bones while at work for Amazon.

Staff will be expected to be working hard on Friday as shoppers are expected to scramble for big deals ahead of Christmas

Amazon staff will protest at five UK centres on Friday. Pictured: Amazon's fulfillment centre in Swansea, in the run up to Black Friday

However, the online giant denied any service disruption would take place.

They said in a statement: 'Our European Fulfillment Network is fully operational and we continue to focus on delivering for our customers.

'Any reports to the contrary are simply wrong.'

However, GMB general secretary Tim Roache said Amazon must improve conditions for it's factory workers.

He said people are 'not robots' and said Amazon must negotiate with workers – as the union advocates for them but is not able to strike deals on their behalf.

He said: 'The conditions our members at Amazon are working under are frankly inhumane.

'They are breaking bones, being knocked unconscious and being taken away in ambulances.

'We're standing up and saying enough is enough, these are people making Amazon its money. People with kids, homes, bills to pay — they're not robots.

'Jeff Bezos is the richest bloke on the planet; he can afford to sort this out. You'd think making the workplace safer so people aren't carted out of the warehouse in an ambulance is in everyone's interest, but Amazon seemingly have no will to get round the table with us as the union representing hundreds of their staff.'

The protests could coincide with a planned walkout at Amazon's large Madrid factory, while staff are being encouraged to down tools in Poland, Italy and Germany, BuzzFeed reported.

Although extremely popular for online shopping the business has come under fire recently.

Earlier in the year it was revealed workers have required ambulances at Amazon factories 600 times in three years.

Amazon has denied there will be any disruption to delivery over the weekend after the Black Friday sale. Pictured: Amazon's fulfillment centre in Swansea

A statement from Amazon denied there would be a problem this week as planned protests did not, to their knowledge, involve staff supposed to be on shift.

It said: 'We are a fair and responsible employer. We believe in continuous improvement across our network and maintain an open and direct dialogue with our associates.

'These are good jobs with highly competitive pay, full benefits, and innovative training programs like Career Choice that pre-pays 95% of tuition for associates. In the UK, as an example, we recently increased the Amazon wage to start from £9.50 an hour and in the London are from £10.50 an hour.

A spokeswoman also said emergency services being called were at a 'dramatically low' level for warehouses of their kind.

She added: 'Ambulance visits at our UK FCs last year were recorded at 0.00001 per worked hour, which is dramatically low.

'Requests for ambulance services at our fulfilment centres are predominantly associated with personal health events and are not work-related.

'Amazon is a safe place to work, according to the UK Government’s Health and Safety Executive, Amazon has over 40% fewer injuries on average than other transportation and warehousing companies in the UK.

'We encourage everyone to compare our pay, benefits, and working conditions to others and come see for yourself on one of the public tours we offer every day at our centers across the UK.'