A source close to Microsoft has revealed that there will be no way for smartphones running Windows Phone 7 to upgrade to Windows Phone 8 when it comes out later this year.

If true, this would mean that the Nokia Lumia range - including the upcoming Lumia 900 - will not get Windows Phone 8, undoubtedly annoying owners who were hoping to upgrade to the new OS.

Speaking to technology website The Verge, the "trusted source close to Microsoft" revealed the bad news after Microsoft developer evangelist Nuno Silva stated that every Windows Phone sold to date will get the "next major update" - which was taken to mean Windows Phone 8, codenamed Apollo.

After Silva's confirmation, Microsoft said in a statement: "We have nothing to share about future releases. All apps in our Marketplace today will run on the next version of Windows Phone."

Microsoft is being careful to say that current applications will work on the next operating system, but fails entirely to mention hardware and also doesn't explicitly state that the "next version of Windows Phone" is indeed Windows Phone 8, or Apollo.

With the flagship Nokia Lumia 900 not due out in the UK until May, the lack of a Windows Phone 8 upgrade on the horizon could spell disaster for Nokia, which has already seen poor sales of its Lumia range of smartphones since they went on sale late last year. It reported last week that it had sold just two million Lumia smartphone in the first three months of 2012, globally.

The news comes just one day after a Reuters story claims European phone carriers have expressed disappointment with the Lumia range, saying the phones aren't innovative and have suffered from a lack of marketing and poor public image caused by early battery and software problems.

"No one comes into the store and asks for a Windows phone," an executive at a European operator told Reuters.

Earlier in April Nokia lowered expectations for its financial results for Q1, causing its share price to fall more than 14 percent - with the final results due out tomorrow.

Away from its Windows Phone-powered Lumia series, Nokia will be pinning its hopes on the 808 PureView with its astonishing 41 megapixel camera. We saw the 808 at Mobile World Congress in February, but found the phone to run the outdated and under-supported Symbian operating system - and Nokia has yet to show off the quality of those vast photographs.