We're at the end of a project, but we continue to run into issues because of a single piece of the project. This piece is handled by a specific developer. Finally, we grabbed latest and started reviewing it. It's just horrendous code! Trying to step through it was difficult and it's a relatively simple workflow.

The point of this question is, how to deal with this situation. The developer has a hard time accepting criticism (constructive or otherwise) and feels he is more knowledgeable than others on the team who are, well, highly decorated, experienced and accomplished developers. It's difficult to even get into a topic about development because it turns into "I know what I'm talking about and you're just wrong!" type of conversation.

A request has already been put in to replace this developer but it is a hard sell since devs are in short supply where we are and this is a corporation with a LOT of political bs.

Management has been notified a few times but nothing is happening.