Phil Collins playing the drums in 1996

At 65 years old, he's at the age when most of us would be looking to put our feet up and relax.

But Phil Collins is instead preparing for a gruelling comeback tour – going to extreme lengths to make sure he is fit enough to perform.

The star is undergoing controversial electroshock therapy in a bid to overcome problems with his spine, neck and arm.

The painful treatment sends waves of electrical current through the body.

Collins, who also has problems with his right foot, is spending two hours a day in the gym to get fit ahead of his Not Dead Yet tour.

The former Genesis star, who has sold more than 150million records worldwide, said: 'I had back surgery, and that went well, but it left my right foot numb which is nerve damage.

'And that has got to regenerate, because the nerves between the foot and your back – that is a long distance.

'I am not that tall, but it is a long enough distance for about a millimetre a week [to have to regenerate], so I have just got to get back and get at it.

'I am doing water therapy now and will be back doing physiotherapy again, and will nudge it along a bit with electroshock things.'

The singer, who is worth £110million, is due to perform in Hyde Park, alongside a five-night stint at the Royal Albert Hall, for which tickets sold out in just 11 minutes.

He had major back surgery which left him relying on a walking stick, just 15 months ago. Collins said he hopes to perform more shows next year – but admits it is all dependent on his health.

Collins, who also has problems with his right foot, is spending two hours a day in the gym to get fit ahead of his Not Dead Yet tour

Speaking on Johnnie Walker's Radio 2 show, he said: 'There might be some more. But I think a question of what effect it takes on me physically as I'm not a man of my age as Tony Hancock used to say so I [can't] just jump back on the bus, but do it in a way that is sensible. I have to keep reminding myself that I am old school and when you went away on tour, it is like going away to war; you don't know when you will come back.

'Life doesn't have to be like that any more and I won't put myself through that now.' While he is desperate to return to drumming full-time, his son Nicholas will play the instrument in his shows.

A source added: 'Phil has a drumkit in his garage at home which he takes a turn on every now and then, and for the past few months he has really been hammering the physio.

'He is about to start electroshock therapy… to kickfire the nerves and instigate a healing response in the area. It will be painful but Phil is braced for it.' Plagued by ill health in recent years, Collins lost hearing in his left ear in 2000. Drumming in the 2007 Genesis reunion led to a dislocated vertebra in his neck – damaging nerves in his hands. In 2011 he said he was focusing on his family, only to come out of retirement.

The singer, who is worth £110million, is due to perform in Hyde Park, alongside a five-night stint at the Royal Albert Hall, for which tickets sold out in just 11 minutes