Local authority IT directors have called on the Office of Government Commerce to allow them to play a greater role in negotiating software licence agreements with suppliers.
The Society of IT Management (Socitm) issued the call ahead of a Commons Public Accounts Committee report on public sector purchasing of software licences due out later this week.
Socitm pioneered a licensing agreement with Microsoft that cut costs for local authorities, and collaborated with the OGC to win deals from Oracle, Sun and IBM for the whole public sector.
But Bob Griffith, international secretary at Socitm, who was closely involved with the Microsoft deal, said although the deals had saved taxpayers money, local government remained a "junior partner" to the OGC.
"The OGC is now playing the dominant role in software licensing negotiations and there obviously needs to be more of a sharing role," he said.
Giving evidence to the committee, OGC chief executive Peter Gershon said he needed the combined purchasing power of the whole public sector to get the best deals. But Griffith said open-source options could be used as a bargaining tool by public sector negotiators discussing licensing terms with Microsoft.
Last month Newham Council secured a new deal from Microsoft, after trialling Linux, that could save the London borough up to £1m. Some experts believe Microsoft can be forced to offer concessions to other councils.