The Hospital Club 100 list will cover the PR, marketing, events, TV, film, art and fashion industries. Media and creative professionals will be able to vote using the club's social network website, launched last year.
'We instituted the ranking partly as a reaction to the hundreds of lists that only measure power by the size of a person's office,' said The Hospital Club head of comms Juliet Haygarth.
Each person who registers is entitled to nominate up to five people. A shortlist will be selected in June for people to vote on. The official list will be announced in July.