GPL and in-house plugins

I’m having a struggle with our legal dept. and need some confirmation on in-house plugins.

We use WordPress for our company website and have developed custom plugins that connect to our backend services. We don’t sell or redistribute these plugins, they are for in-house use only.

Our Legal Eagles are under the impression that the GPL2 license requires that we make these plugins available to the public, as well as the back end code they connect to.

Of course, this is not my reading of the GPL, but I need something I can give to then that would convince them that we are not required to make this code available to anyone.