A multi-layer flexible hose is described comprising a multi-layered structure that has an inner, hollow tube comprising PTFE and an outer layer. The inner PTFE tube is provided so as to extend within the outer layer. The assembly further comprises another sleeve comprising steel braiding that is positioned between the inner PTFE tube and the outer layer. In addition to this, the hose further comprises a coating or layer of intumescent material that is provided between the steel braiding sleeve and the outer layer. A method for forming the hose is also described.