8. Michael Ashcroft
Michael Ashcroft’s fortune comes from buying and selling a number of companies, most notably home security giant ADT.
He purchased ADT in 1987 then flipped it to Tyco International in 1997 for $6.7 billion; proceeds from the sale still form the bulk of his fortune.
A longtime Conservative Party supporter, he served as deputy chairman from 2005 to 2010, and stepped down from the House of Lords in March 2015.
Ashcroft is also a major investor in Belize and previously served as the Belizean Ambassador to the United Nations from 1998 to 2000.