A method of on-press developing a thermosensitive lithographic printing plate with ink and/or fountain solution is described. The lithographic plate comprises on a substrate a thermosensitive layer soluble or dispersible in ink and/or fountain solution and capable of hardening upon exposure to an infrared radiation. The printing plate can be a pre-coated plate in the form of sheet or web, or can be prepared on press by coating a thermosensitive layer onto a substrate that is a sheet material or a seamless sleeve mounted on a plate cylinder or is the surface of a plate cylinder of the lithographic press.