BBC and Newsnight presenter Jeremy Paxman is giving evidence at the Leveson inquiry into press standards.
Earlier fellow BBC presenter Andrew Marr told the inquiry he had taken out a super injunction to prevent details of an affair being reported because the Press Complaints Commission was too weak to do anything.
Marr said that the country had looked "agog" at some of the evidence presented so far, but that the newspaper industry could be fatally injured by too much regulation.
"Without individual contacts... and a bit of wining and dining... I don't think the public would have known about the difficulties in the Brown/Blair relationship... and that was a really important story," he said.
Former Labour defence secretary Lord Reid and Tory MP Stephen Dorrell, who oversaw media policy as heritage secretary in John Major's Conservative government in the mid 1990s, were also called to give evidence on Wednesday.
The inquiry, sitting at the Royal Courts of Justice, is to hear from Culture Secretary Jeremy Hunt's former special adviser Adam Smith and News Corporation lobbyist Frederic Michel on Thursday.