And Lily Buxton, 69, who travels daily by taxi to play bingo, described how she burst into tears when a receptionist told her of Dr Gordon Khan's decision by phone and advised her to catch a cab.
Mrs Buxton said: 'She said 'We have seen your photograph in the paper winning all that money and you are asking for a sit-down ambulance. There's no way you are getting one'.
'I got the shock of my life when she told me to get my own taxi. I started crying.'
Mrs Buxton, who scooped her jackpot prize three weeks ago, was told to pay the pounds 10 taxi fare herself. Her twice-daily taxi bill to her bingo hall is pounds 4.80.
Mrs Buxton, an arthritis sufferer, of Skelmersdale, Lancashire, has lodged an official complaint with the local Family Health Service Authority.
But Dr Khan, 56, a GP for 29 years, is confident the investigation will back his decision.
'The state of the ambulance service is such that it cannot deal with all emergencies,' he said.
'Last Monday one of my women patients had to take her sick child to hospital herself because there was no ambulance available.
'The ambulance staff say they are behind me and wish more doctors would say no.'