A minicab driver has admitted bombarding Jemima Khan with more than 1,000 phone calls and messages.
Hassan Mahhmood, 27, pleaded guilty to carrying out a campaign of harassment for more than a year.
Isleworth Crown Court heard he became obsessed with the 43-year-old after she posed for a “selfie” with him.
Mahhmood got the journalist’s number when she booked a taxi through ride-hailing service Halo, the court heard.
He called her mobile phone 1,182 times, sent her 203 text messages and sent her “loads” of WhatsApp messages.
Prosecutor Ruxana Ali said the defendant told Khan, who is also known by her maiden name Goldsmith, that he “loved her”, “wanted to know her” and asked her “why he could not be friends with her”.
Ms Ali said Mahhmood used 18 different mobile phones to contact her.
Khan, who is the daughter of the late billionaire entrepreneur Sir James Goldsmith and sister of MP Zac Goldsmith, finally spoke to police after Mahhmood told her he wanted to visit her home.
The driver’s barrister Umar Ali said the defendant was a “big fan” of Khan because of her marriage to his hero, Pakistan cricket legend Imran Khan.
Mahhmood, of Waltham Forest, north-east London, pleaded not guilty to a more serious charge of stalking the campaigner, which was allowed to lie on file.
Judge Martin Edmunds QC adjourned sentencing to a later date.