Jemima Khan (L), Hassan Mahhmood (R)

Jemima Khan, the former wife of cricketer-turned-politician Imran Khan, said she has been ?forced to move house? after an obsessed black cab driver in London bombarded her with thousands of calls and text messages after saving her mobile phone number.

Pakistani-origin cab driver Hassan Mahhmood, 27, a self-proclaimed die-hard fan of Imran Khan, began harassing Jemima after she agreed to pose for a picture with him at the end of her ride in London last year.

Mahhmood sent her 203 text messages and called her 1,182 times over the year, telling her he was in love with her and wanted to be her friend because she had been married to his ?hero? Imran Khan.

In a court hearing earlier this week, he admitted harassment, which carries a six month maximum jail term.

Jemima, the daughter of late billionaire tycoon Sir James Goldsmith, blocked his number several times but to no avail: he changed his phone numbers 18 times.

Jemima and Imran Khan pictured together in 1996/Getty Images 

She did not approach police fearing he would 'take revenge' if he lost his job or was arrested, according to media reports.

?At times I would be home alone, and he would call me several times, and text repeatedly late at night,? she was quoted as saying by Daily Mail.

?Sometimes he said in texts that he would come to my house. That would really frighten me. I would ask friends to stay. Often I would hear noises and not sleep.

?I am planning to reluctantly move house. He seems to have increasingly become unstable and unpredictable, and I am worried about what he will do,? she said.

Mahhmood told the court his marriage had broken down in May (he had got married in 2015) and his black cab license had been revoked.