Head transplants could one day lead to immortality, the Italian surgeon pioneering the procedure has said.

Sergio Canavero has made headlines across the globe after announcing his plans to perform the world's first head transplant (or full body transplant if you prefer).

He said he believes the first surgery will take place in 2017 and already has a willing donor ready to undergo the knife. However, his plans have also been met with widespread condemnation, with many experts extremely critical of both the procedure and the ethical implications.

Hunt Batjer, president elect of the American Association for Neurological Surgeons, for example, said it was a "fate worse than death". "I would not wish this on anyone. I would not allow anyone to do it to me as there are a lot of things worse than death," he told CNN in April.

However, speaking to Italian website LaPresse.it, Canavero said he has found "dozens of sponsors ready to finance the project", as well as doctors and surgeons who are willing to participate in the operation.

"If all this money is on the way, that means that someone really believes in this project, otherwise people would not throw away their money," he said. The surgery will require about $10m (£6.4m) worth of investments and 150 staff – including doctor and assistants.

In total, the operation is expected to last around two days. First the patient's head will be cooled down then removed. It will then be attached to another body – the spinal cords of patient and donor will be cut, and the head will be moved across to be fused together.

Muscles and blood supply would then be attached and the patient would be left in a coma for about a month to prevent any movement – during this time the spine would be stimulated with electrodes to strengthen nerve connections.

Canavero told the website: "The head that is going to be transplanted gets frozen at 12 degrees. Then, we can proceed to sever both heads – including blood vessels, muscles and bones – and it begins the phase when the patient receives the new head."

He said his procedure could be the first step in achieving immortality: "We are one step closer to extend life indefinitely because when I will be able to give a new body to an 80-year-old they could live for other 40 years".

He believes it will take about five years to perfect the technique, after which it will have "unimaginable consequences" and will "forever change the story of humanity".

Responding to his critics, Canavero said people feel threatened because they have not produced results like his, along with the "mental limitations" involved in the surgery – such as the fear of extending life forever.

He also said people are worried the procedure will be confined to the rich: "One of the reasons behind the critics is that many wealthy people will want a new head, as they will be the only ones who could afford the surgery."