The Sunday red tops are expected to cut their cover prices by as much as half this weekend to ensure their readers are not snared away by The Sun's new Sunday edition.
Rupert Murdoch's announcement that The Sun will cost just 50p this Sunday has sparked a tabloid price war.
Richard Desmond will match Murdoch by halving the cost of The Daily Star Sunday from £1 to 50p.
And Media Guardian reports that The Sun's big rivals at Trinity Mirror - which gained a huge spike in readers after the demise of the News of the World - will cut their cover price to 50p in some regions.
It claims The Sunday Mirror and the People will be slashed from £1 to 50p in London, the South coast and the Midlands.