A 79-year-old man was left in agonising pain as he suffered a stroke that partially blinded him while he waited hours for an ambulance to arrive.

The wife of stroke victim John O’Shea could only watch helplessly as he writhed in pain while blood poured from his right eye at their bungalow in Brassey Road, West Hampstead.

Retired nurse Kate O’Shea, 74, has written to health secretary Andrew Lansley railing at the lack of resources that left her husband without medical attention for three hours.

She said: “We have relied on the NHS and we’ve been very appreciative of it, but this situation where the budget has been cut across every aspect of the NHS is just unbearable.

“The ambulance people told me ‘It’s not only happening to you but lots of people and we just don’t know what to do - we’re trying to figure out who we have to take and who to say no to’. That’s a terrible situation.”

On Easter Monday at 2am retired dental technician Mr O’Shea woke up suffering a piercing pain in his head and 20 minutes later he lost the sight from his eye.

Fearing he had a brain tumour, his wife contacted the out of hours GP service but was told to ring 999.

Despite placing an emergency call at 2.02am the couple was forced to endure an excruciating wait as operators told them an ambulance had been diverted to a life-threatening situation.

Mrs O’Shea, who uses a wheelchair because of rheumatoid arthritis, said: “I was just so upset by the extent of his pain. He was clutching his head, saying ‘I can’t stand it, I can’t stand it’.”

An ambulance finally arrived between 5.15am and 5.30am and took Mr O’Shea to the Royal Free Hospital, where it was confirmed he had suffered a mini-stroke caused by a brain haemorrhage.

His memory and sight have both been affected and he is not expected to return home for at least two months.

Although consultants confirmed that the type of stroke Mr O’Shea suffered was not worsened by the delay in the ambulance arriving, his wife said the extent of the pain he suffered without treatment was unacceptable.

A spokeswoman for the London Ambulance Service (LAS) claimed that an ambulance reached the scene at 4.46am.

She said: “Our call taker was able to confirm that the patient was conscious and alert, but unfortunately we were not able to attend immediately.

“We would like to apologise for the delay in reaching the patient, and for any distress caused to him or his family.”

LAS invited the O’Sheas to contact the patient experiences department on 020 3069 0240.