gpl licensing

[miguelx6]

Hello,
I'm going to develop a project for public administration. They will be
the users of this software, they are not going to sell it. After
finishing the project, I have to deliver all the sources to them, so I
will not own the sources after that. My question is, could I use gpl
libraries? I am working for a company and they are going to pay us for
this project, but, as I am delivering them all the sources, I suppose
ther should be any problem.

Sorry, but it is really complex licensing issues for me.

Thanks
Miguel