This paper presents the formulation of a triangular finite element with an embedded interface, designed for the simulation of discrete crack propagation processes. The element is developed within a displacement-based framework. Linear interpolation of the displacement discontinuities along the internal interface is assumed in order to ensure compatibility across inter-element boundaries. The proper representation of the rigid body motions and the solvability of the discretised version of the mechanical problem in point are specifically addressed. Finally, the element performance is illustrated through comparison with some alternative proposals.