Selected journalists were invited to Number 10 for a briefing from officials on Monday, but correspondents from organisations who were not on Downing Street's hand-picked list also tried to get in, the Metro newspaper said in a report.
According to those who were present, when political correspondents arrived inside Number 10 they were asked their names and told to stand on opposite sides of the entrance hall.
The Independent's political editor Andy Woodcock said Number 10's Director of Communications Lee Cain then invited those on one side to enter and asked those on the other to leave.
In protest at the treatment of colleagues, all the journalists present chose to walk out rather than receive the briefing.
The Guardian's Deputy Political Editor Rowena Mason said that among those who refused the briefing and walked out were the BBC's Laura Kuenssberg, ITV's Robert Peston and journalists from the Daily Mail, Telegraph, the Sun, and Financial Times.
"I felt deeply uncomfortable being left to stand on one side of the room while colleagues' names were read out one-by-one and they joined the group who were deemed 'acceptable' by No 10. Sinister and sad," the Metro quoted the Daily Mirror's political editor Pippa Crerar as saying.
Monday's development is the latest sign of the strained relationship between Number 10 and political journalists, the Metro report said.
Johnson's Brexit day "address to the nation" was filmed by Downing Street, rather than a crew from a TV network as would usually be the case leading to criticism from broadcasters.
Lobby correspondents - the political journalists based in Westminster - have also seen their regular briefings moved from Parliament to 9 Downing Street, raising fears about the prospect of Number 10 banning reporters.
( With inputs from IANS )