High contrast photographic element containing a polyhydrazide nucleating agent

A process of forming a photographic image having ultrahigh contrast which comprises imagewise exposing a photographic material comprising a support bearing a silver halide emulsion layer and processing it with an alkaline developer solution, characterised in that it is developed in the presence of a nucleating agent of formula (I),

• wherein
• each A1 and each A2 is independently selected from the class consisting of a hydrogen atom, an unsubstituted or substituted acyl group and an alkyl- or aryl-sulfonyl group;
• each Y is independently selected from the class consisting of an unsubstituted or substituted aryl or heterocyclic ring or ring system;
• each X is independently selected from the class consisting of S═O, C, C—NH and C—O;
• each L′ is independently selected from the class consisting of an unsubstituted or substituted alkylene group and an unsubstituted or substituted aryl or heterocyclic ring or ring system, linked to Z via an unsubstituted or substituted alkylene group, either directly or via a group selected from the class consisting of NR1CO—, NR1CONR2—, OCONR1— or NR1COO—, wherein R1 and R2 are independently selected from the class consisting of a hydrogen atom and an unsubstituted or substituted alkyl group;
• each Z is independently selected from an unsubstituted or substituted group, ring or ring system attached via a heteroatom selected from the class consisting of sulfur, nitrogen, oxygen or phosphorus;
• each L is independently a divalent, trivalent or tetravalent linking group;
• p and each n are independently 0 or 1
• k is an integer from 0 to 8;
• and m is an integer from 2 to 4 provided that when p is 0, n is 0 and m is 2;
• when p is 1, n is 0 or 1 and m is 2, 3 or 4;
• and
• T is a counterion or a salt forming acid.