Blogger Guido Fawkes claims he has a list that shows key donors include:
Lady Annabel Goldsmith, mother of Jemima Khan and Zac Goldsmith.
Jewish billionaire Lord Sainsbury, who was one of Labour's biggest financial backers under Tony Blair.
Hacked Off Donors: #6 Billionaire Labour Lord Sainsbury
According to the UK government:
"However, those ‘relevant publishers’ that choose not to join the regulator would be subject to costs and could be subject to exemplary damages if taken to court.
"‘Relevant publishers’ are specifically defined and could include blog sites that are written by multiple authors, have editorial control and are published in the course of business."
Downing Street Say Guido is a “Relevant Publisher”