University of London (UoL) lecturers will send a letter to bosses today in protest at the criminalisation of students who chalked slogans on campus.

Sponges, wash clothes and instructions on how to remove chalk from a surface with "gentle circular motions" will be attached to the open letter.

It reads: "Hearing that you had recently experienced some trouble involving chalk marks being made on your foundation stone, we pooled our collective knowledge and, after many strenuous hours of discussion, came up with what we humbly submit is the best possible solution to your problem."