Abstract: Carbon fibre precursors for use in the formation of carbon fibre materials. The carbon fibre precursors comprise fibres of polymeric material which have a coating layer thereon, the coating layer comprising a material susceptible to dielectric heating, for example carbon nanotubes. The carbon fibre precursors may be suitable for forming into carbon fibres using a dielectric heating step, despite the fibres of polymeric material not being susceptible to dielectric heating, without adversely affecting the structure and physical properties of the main body of the carbon fibre so formed. A method of preparing a carbon fibre precursor for a carbon fibre formation process and a method forming a carbon fibre are also disclosed.