Necessary conditions in the form of Pontryagin's maximum principle are derived for impulsive control problems with mixed constraints. A new mathematical concept of impulsive control is introduced as a requirement for the consistency of the impulsive framework. Additionally, this control concept enables the incorporation of the engineering needs to consider conventional control action while the impulse develops. The regularity assumptions under which the maximum principle is proved are weaker than those in the known literature. Ekeland's variational principle and Lebesgue's discontinuous time variable change are used in the proof. The article also contains an example showing how such impulsive controls could be relevant in actual applications. © 2011 Elsevier Ltd. All rights reserved.