A European Commission working paper on linking national government IT systems across Europe is recommending open source software.
The paper, Linking up Europe: the Importance of Interoperability for E-government Services, stressed that the planned European interoperability framework should be "based on open standards and encourage the use of open source software".
Andy Butler, vice president at analyst Gartner, described it as "a loaded statement" which will be "very provocative".
He warned that it would be a mistake to equate open source with open systems, and pointed out that there will always be cases when proprietary applications are preferable to open source.
"There are some people in Europe who are passionate about open source. For them, Linux is not an operating system but a religion and they could start to go over the top," said Butler.
He added that Microsoft in particular would view this development with alarm, but the Redmond giant was cautious in its response.
"The most critical point is there needs to be neutrality in procurement, said Wilfried Grommen, Microsoft general manager of business strategy for EMEA.
He said Microsoft was positive about adherence to open standards but some people did not understand the difference between this and open source.
"Our only concern is that people and governments judge software on total cost of ownership and real business values and benefits."
The European Commission paper seeks to gain acceptance from policy makers on the need for interoperability in Europe at all levels, and "to ensure that any consequential adjustments of European or national policies occur".
It is critical of past developments which "resulted in closed, vertical, un-scalable and frequently proprietary information systems".
The paper is part of an ongoing implementation of the eEurope initiative which was approved at the European Council in Seville in June last year.
Its ambitious goal is to make the European Union "the most competitive and dynamic knowledge-based economy in the world" by 2010.
From the eEurope initiative came the eEurope 2005 Action Plan for an EU interoperability framework to support the delivery of pan-European e-government services to citizens and enterprises.
The European Commission is tasked with issuing an agreed framework format this year, and the first version is due to be issued for consultation in September. Its guidelines can be found here
The working paper can be accessed here. The eEurope 2005 Action Plan can be seen here.