The iPhone has been removed from the first-ever UK ranking initiative for rating smartphones' eco-friendliness.
Apple's major rivals including Nokia and Samsung have agreed to submit their mobiles to the project, which will assign a star rating up to a maximum of five so that consumers can judge the environmental viability of a particular model.
Network provider O2 is spearheading the project and claims that 93 per cent of the mobiles that it offers to its customers will get a rating under the scheme.
Researchers from Forum for the Future will be working with O2 to judge how the components, production, transport and lifespan of a mobile will impact upon the environment.
Apple has not only withdrawn the iPhone from the scheme, but it has also refused to release any comment as to precisely why it will not be joining in with the competing firms.
"Transparency is always an issue for consumer electronics companies, who claim that providing too much information gives away competitive advantage. Whilst Apple has recently made important strides in eliminating toxic chemicals from its products and the reporting of their environmental footprint, it still lags behind others in transparency," said Greenpeace spokesperson Gary Cook.
Apple has been the target of both criticism and praise by Greenpeace and other eco-activists and this latest move could tip the balance in a negative direction.
Manufacturers will be faced with 63 questions which the project organisers will then use to assign a ranking.
"The largest impact comes from the energy used in extracting materials [from the Earth] and transporting them, as well as the energy and water used to process components such as silicon wafers," explained Forum for the Future's James Taplin.
Unsurprisingly, it was Sony Ericsson's eco-friendly Elm mobile that got one of the highest rankings, scoring 4.3 out of a possible five. The greatest proportion of its points were awarded because its multipurpose extra functions, such as media playback and photography capabilities, meant users would not be buying standalone gadgets.
"You need to look at the indirect impact of the phone, such as fewer devices, not just the phone," Mr Taplin added.
Three of Nokia's mobiles drew with the Sony Ericsson Xperia X10 variants and the Samsung GT-S8500 to take second position on the rankings with a solid score of four out of five.
11.5 per cent of respondents to a survey said that green credentials would have an impact on their choice of mobile phone.