You ought to instate code reviews where the senior developers review the code of the other developers. If they don't follow convention, they fail the code review and it won't make it into the repository.
This requires a bit of human-engineering in that it is more process-based than software-based.
Oh, and tight deadlines are no excuse for bad code. As programmers it's our job to write solid quality code that is maintainable by the rest of the team.
