Max Clifford has been told he must serve at least half the eight-year sentence handed down at Southwark Crown Court in prison.
Judge Anthony Leonard told Clifford he had shown a "contemptuous attitude" and "quite extraordinary behaviour" while showing "no remorse" for his crimes.
The judge said: "These offences may have taken place a long time ago, when inappropriate and trivial sexual behaviour was more likely to be tolerated, but your offending was not trivial, but of a very serious nature."
More top news
Former Scotland football captain Colin Hendry has admitted harassing his ex-girlfriend over a two-month period.
Scientists say they have identified three proteins that can indicate when the disease is present.
Sue and Alex Tatham are still together after meeting on the show 27 years ago and now have two children.