Speaking to the Sunday Times magazine, Petra said she could no longer tolerate how dangerous it feels living in the capital.
'It's crazy how unsafe the UK has become — so much more so than 10 years ago,' she said.
'Talking with mums at school, there have been so many incidents, so many attacks, robberies, knives during the day. You don't feel safe walking around the neighbourhood.'
She now employs four bodyguards as a result, including one to protect herself and one her for her three young children Lavinia, five and twins James and Andrew, three.