Lithographic printing plate precursor comprising: a) an untreated or pretreated substrate and b) a radiation-sensitive coating comprising: (i) at least one polymeric binder soluble or swellable in aqueous alkaline developers; (ii) at least one free-radical polymerizable monomer and/or oligomer comprising at least one non-aromatic C--C double bond and at least one SH group in the molecule; and (iii) a radiation-sensitive initiator or initiator system for free-radical polymerization, wherein component (ii) has the formula (I) wherein each R.sup.1a, R.sup.1b and R.sup.1c is independently selected from H, C.sub.1-C.sub.6 alkyl, C.sub.2-C.sub.8 alkenyl, aryl, halogen, CN and COOR.sup.1d, wherein R.sup.1d is H, C.sub.1-C.sub.18 alkyl, C.sub.2-C.sub.8 alkenyl, C.sub.2-C.sub.8 alkynyl or aryl; and Z is an aliphatic, heterocyclic or heteroaromatic spacer or a combination of two or more thereof, wherein Z can optionally comprise one or more additional SH groups and/or one or more additional non-aromatic C--C double bonds; and each Z.sup.1 is independently selected from a single bond, formulae (Ia), (Ib), (Ic), (Id), (Ie), (If), (Ig), (Ih), (Ij), (Ik), (Im), (In), (Io), (Ip), (Iq), (Ir), (Is), (It), (Iu), (Iv), wherein R.sup.2a, R.sup.2b and R.sup.2c are independently selected from H, C.sub.1-C.sub.6 alkyl and aryl, Z.sup.2 is selected from a single bond, O, S and NR.sup.2c, Z.sup.3 is a single bond which is connected to Z, b is an integer from 1 to 10 and c is an integer from 1 to 3. ##STR00001## ##STR00002##