The nucleon is formulated as a relativistic system of three constituent quarks interacting via a zero-range two-body force in the null plane. The covariance of the null-plane Faddeev-like equation under kinematical front-form boosts is discussed. The nucleon wave function is obtained from the numerical solution of the Faddeev equation in the null plane. The proton electric form factor, obtained from the Faddeev wave function, reproduces the experimental data for low momentum transfers and qualitatively describes the asymptotic region.