As the spouse of an EU citizen who lives and works in the UK, your husband can enter the UK under the freedom of movement directive, or, more precisely, under the UK's implementing regulations. The only grounds for refusal are a finding that your husband represents a threat to public safety or public health, that his presence would be contrary to public policy, or that your marriage is a marriage of convenience or otherwise invalid.
Prior immigration violations are not generally grounds for refusal, therefore. If his past behavior could make him liable to prosecution, though, you should consult a lawyer, since his entering the UK could lead to his being prosecuted.
If your husband has a visa-exempt passport, he can just travel to the UK and be prepared to make his claim under the regulations at the border. If he requires a visa, he should apply for an EEA family permit. Even if he does not require a visa, he might want to apply for an EEA family permit anyway, since that would relieve him of the stress of having to make his case at the border, which comes with the possibility of being sent back home if his application is not successful.