She blasted “that sort of objectification of women” as something “I thought… that we were leaving behind”, adding there was “much more for us to do”.
Her spokesman also hinted the Government could crack down on gagging orders, after the more than 100 female hosts at the Dorchester Hotel dinner were ordered to sign non-disclosure agreements.
Speaking in Davos, Switzerland, the Prime Minister said: “When I read the report of that event that took place, frankly I was appalled.
“I thought that sort of approach to women, that sort of objectification of women was something that we were leaving behind. We’ve made progress but it’s very clear that there is much more for us to do.
“What I want to see and I will continue to work to a point where women are genuinely accepted and respected as equals.
“I’m not happy with an event of that type taking place. I was appalled by the reports that I read. What worries me is that it’s not just about this event. It’s about what it says about this wider issue in society about attitudes to women.”
Questioned about the newly-promoted children and families minister Nadhim Zahawi attending the event held last Thursday, Mrs May said she understood he “left early”.
Mr Zahawi claims he arrived at the dinner at 8pm and left 90 minutes later as he felt “uncomfortable” – but “did not see any of the horrific events” originally reported by the Financial Times.
A Government official who was also a joint chair of the Presidents Club has been forced to resign and the group has scrapped all further events.
Two hospitals, including Great Ormond Street, have announced they will hand back all funds received from its fundraisers.
Female staff reported being groped and propositioned at the dinner of around 360 guests that included lunch with Foreign Secretary Boris Johnson and tea with Bank of England governor Mark Carney as auction items.
Both have said they were unaware of being used as prizes.
Attendees included celebrities and other leading figures from finance, business and politics.
Hosts were reportedly told to wear skimpy black dresses and matching underwear, with one told by a guest she was “far too sober”. He then declared: “I want you to down that glass, rip off your knickers and dance on that table.”
The event was dubbed a “lady zoo” for “slimeballs” by furious MPs, with minister Anne Milton admitting: “Words fail me.”
A spokesperson for the Presidents Club said the event raised over £2m for disadvantaged children.
But they added: “The organisers are appalled by the allegations of bad behaviour at the event asserted by the Financial Times reporters.
“Such behaviour is totally unacceptable. The allegations will be investigated fully and promptly and appropriate action taken.”
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The Dorchester insisted it had a zero-tolerance policy to harassment of employees and guests.
It said: “We are unaware of any allegations and should we be contacted we will work with the relevant authorities as necessary.”