Amazon has been accused of 'sneakily' introducing a new charge for customers using its same-day Prime Now delivery service.

The online shopping giant has doubled the minimum amount customers need to spend to qualify for free same-day delivery.

The changes mean shoppers will have to cough up a £3.99 delivery cost plus a optional £2 tip for the driver on Prime Now orders under £40, even if you're a £79-a-year paying Prime subscriber, the Mirror reports .

That's despite Prime selling itself as the online subscription that offers free unlimited deliveries for a year.

Before the change, Amazon had a minimum order of £20 to qualify for free same day (within two hours) deliveries through Prime Now.

Now, the minimum order has come down to £15, however any order below £40 comes with the £3.99 fee.

It's now been slammed by shoppers who have described the move as a 'rip off'.

One disappointed Prime member tweeted: "AmazonUK pay for AmazonPrime and now get hit with additional £3.99 charge? #joke #ripoff."

Another described it as 'sneaky', adding they are tempted to cancel their subscription altogether.

"It’s clear the new 3.99 charge for prime now is to reduce business and make money. Sneakily added and going to annoy people paying for AmazonPrime I’m one thinking about cancelling."

The US firm's shake up now risks alienating customers with those on its subscription service no longer having access to free unlimited deliveries, the reason why many originally signed up.

Twitter user @Vampraist went on to add the charge is an 'insult' to loyal Amazon Prime members.

"amazonprimenow your minimum £40 order no delivery charge is insulting for amazonprime members with many years of loyalty/"

Prime Now , which specialises in delivering food, groceries, health, beauty, and home products, launched in 2015.

The retailer, which has been selling dry groceries like bottled water, coffee and nappies for a while, this year expanded to fresh items such as milk, cheese, frozen pizza and butter with delivery within two hours.

It operates in Birmingham, Newcastle, Manchester and Liverpool. In London, it's partnered with Morrisons to deliver food almost instantly .

Amazon staff did not respond to most of the angry tweets regarding the price changes, failing to offer any explanation for it.

When asked to explain the change, Amazon provided a link to its help pages which set out the charges.

The company recorded huge sales worth £1.4billion in 2016, grabbing business from traditional UK retailers, however it paid just £7.4million in corporation tax, which is a tax on profits.

Amazon said: "We pay all taxes required in the UK and every country where we operate. Corporation tax is based on profits, not revenues, and our profits have remained low given retail is a highly-competitive, low margin business and our continued heavy investment."

The minimum spend change isn't the only thing Amazon is currently under fire for. The company been accused of "chopping down the rainforest" for using up to 45 FEET of paper packaging - to protect a wall calendar.

A number of customers have been left scratching their heads in wonder after the standard calendar arrived with massive amounts of packaging - measuring longer than the biggest fish in the ocean, the whale shark.

Annie Gelly purchased the Collins A2 calendar online, but it arrived in a cardboard box so large that she reckons 'could have held ten of them'.

The grandmother-of-one from Herne Hill, south London, said she had been expecting the £8.99 calendar to arrive in a Jiffy bag or envelope and was shocked to see 'such a waste' of paper.

Ann, who is in her 70s, said: "The calendar arrived last Thursday and it has masses of paper in the box - there were nine lengths of screwed-up brown paper which measured about 45 feet in total.

"Amazon always package stuff this way - I've had things like this in the past and they're particularly prone to it - but this really took the biscuit.

"They could have fitted at least ten calendars in that box and I'd expected it to turn up in a cardboard envelope or a Jiffy bag."

Ann and husband Dave, also in his 70s, say they have kept the box to store books but could not find a use for the huge length of paper.

The couple, who have one son and a grandson, added: "It's such a waste, I couldn't use the paper for anything else because it was all scrunched up and it completely filled the recycling bin.

"I think it's bad for the environment and you would have thought Amazon of all people would be aware of that kind of thing and try to be more careful.

"The paper has obviously come off a roll and they've just pulled it off willy nilly, torn it off and scrunched it up until the box was full.

"I think it's a very shoddy and slap-hazard way of packing flat items like calendars.

"It's not a good advertisement for them at all and I'll definitely be complaining about it."

In another order, the length of paper was twice the length of a great white shark - a ream 26ft long.

That customer, who asked not to be named, said: "I know that the paper they use is recycled, but I can't help but think Amazon are still chopping down the rainforest.

"It was so excessive - but on the plus side, I won't need to buy any wrapping paper this Christmas."

Amazon claimed that they are reducing the amount of packing material used and 'ship products in their own packages'.

A spokesperson said: "We continue to pursue multi-year waste reduction initiatives - e-commerce ready packaging and Amazon Frustration-Free Packaging - to promote easy-to-open, 100 per cent recyclable packaging and to ship products in their own packages without additional shipping boxes.

"These initiatives have grown to include more than 1.2 million products over time and have eliminated more than 36,000 tons of excess packaging just in 2015.

"If executed well, our innovations will also help us to reduce prep, packing material and shipping supplies and reduce our operational costs by increasing the use of recycled materials.

"They will also increase the overall density of the packages we ship - good for transportation savings and less waste for our customers - and reduce the things that get damaged in transit and eliminate wasted packaging."

Prime Same Day delivery service remains unchanged and is available in select areas on a million items at no extra cost to Prime Members.