PgSQL driver for .Net?

Hi all,

a German company evaluates migration from of their insurance software
application to an Intranet/Internet application. Currently they are
using MS SQL as database server and MS Access as clients (they
appreciate the RAD capabilites of Access). They are already positive
about the high capabilites of PostgreSQL, thus they evaluate to migrate
the DBMS from MS SQL to PostgreSQL. The system stores several hundreds
of thousands of contracts. They plan to implement native GUI clients for
the Intranet users and a Web application for Web users.

At the moment they seem to prefer a .NET architecture for their target
system. The database server (PostgreSQL) can be hosted on Linux, but
they think its ODBC driver is not appropriate for their needs. They
would prefer a driver for ADO.NET client apps or a native driver (not
DAO). Java is not their architecture of first choice, thus JDBC wouldn't
fit. They did see that I'm volunteer therefor called me today. As I'm
not a developer I forward the question to you: Are there any PostgreSQL
drivers for ADO.NET or a native PgSQL driver for their .NET clients?

Links and/or any help or advice welcome. :) Thank you

Anastasios