A prepreg comprising at least one layer of carbon fibres and a curable thermosetting resin system, the curable thermosetting resin system at least partly impregnating the at least one layer of carbon fibres, wherein the curable thermosetting resin system comprises: a. a curable thermosetting resin including at least one epoxide group; b. a curing agent for curing the curable thermosetting resin, wherein the curing agent is present in the liquid phase and includes a cyanamide reactive group, wherein the curing agent comprises cyanamide of formula NC-NH 2 ; c. an accelerator for accelerating the curing of the thermosetting resin by the curing agent, wherein the accelerator includes at least one urea reactive group, wherein the accelerator comprises a substituted or unsubstituted urea of formula R 1 R 2 -N-CO-NR 3 R 4 , where R 1 is hydrogen or any substituted or unsubstituted aliphatic group, R 2 is hydrogen or any substituted or unsubstituted aliphatic, R 3 is hydrogen or any substituted or unsubstituted aliphatic or aromatic group, and R 4 is hydrogen or any substituted or unsubstituted aliphatic or aromatic group; and d. a rheology modifier for the curable thermosetting resin system, wherein the rheology modifier is a thermoplastic resin, wherein the curable thermosetting resin and the thermoplastic resin of the rheology modifier are present in a weight ratio of from 90:10 to 99:1, wherein the weight ratio of (i) the combination of the curable thermosetting resin and the thermoplastic resin of the rheology modifier and (ii) the combination of the curing agent including the cyanamide reactive group and the accelerator including the urea reactive group is from 100:5 to 100:18, wherein the cyanamide curing agent and the urea accelerator are present in the curable thermosetting resin system in a weight ratio of from 2: 1 to 1:10, and wherein the thermosetting resin system is formulated to have a minimum viscosity during curing of from 6 to 18 Pa.s at a temperature of from 95 to 105 °C. a. a curable thermosetting resin including at least one epoxide group; b. a curing agent for curing the curable thermosetting resin, wherein the curing agent is present in the liquid phase and includes a cyanamide reactive group, wherein the curing agent comprises cyanamide of formula NC-NH 2 ; c. an accelerator for accelerating the curing of the thermosetting resin by the curing agent, wherein the accelerator includes at least one urea reactive group, wherein the accelerator comprises a substituted or unsubstituted urea of formula R 1 R 2 -N-CO-NR 3 R 4 , where R 1 is hydrogen or any substituted or unsubstituted aliphatic group, R 2 is hydrogen or any substituted or unsubstituted aliphatic, R 3 is hydrogen or any substituted or unsubstituted aliphatic or aromatic group, and R 4 is hydrogen or any substituted or unsubstituted aliphatic or aromatic group; and d. a rheology modifier for the curable thermosetting resin system, wherein the rheology modifier is a thermoplastic resin, wherein the curable thermosetting resin and the thermoplastic resin of the rheology modifier are present in a weight ratio of from 90:10 to 99:1, wherein the weight ratio of (i) the combination of the curable thermosetting resin and the thermoplastic resin of the rheology modifier and (ii) the combination of the curing agent including the cyanamide reactive group and the accelerator including the urea reactive group is from 100:5 to 100:18, wherein the cyanamide curing agent and the urea accelerator are present in the curable thermosetting resin system in a weight ratio of from 2: 1 to 1:10, and wherein the thermosetting resin system is formulated to have a minimum viscosity during curing of from 6 to 18 Pa.s at a temperature of from 95 to 105 °C. <EOS>