Speaking at an event to launch a partnership between Newham and Microsoft, Richard Steel -- Newham Council's head of ICT -- insisted that a recent assessment of the various merits of Windows and open source had been fair and above board.
"We weren't playing around. We gave Linux a very serious look," Steel told ZDNet UK on Monday.
Microsoft has said that Newham can look forward to saving £3.2m over five years thanks to this new deal, under which it will deploy 12 different Microsoft products ranging from Office 2003 Professional to SQL Server 2000. Tablet PCs are also being trialled by the borough's social services arm.
The software giant is now citing Newham as proof that its software can deliver greater value than Linux.
But open-source advocates claim that Microsoft made massive concessions to avoid the council taking the open-source road. The phrase "doing a Newham" has even been coined, to describe the act of threatening Microsoft with a defection to Linux in order to drive licence fees down.
Speaking at a press conference on Monday, Steel acknowledged that the competition from Linux had helped to get it a better deal from Microsoft.
"You'd be insane to think otherwise," Steel said.
Consultancy firm Capgemini examined Microsoft's proposed solution last year, and concluded that it was a better bet than the open-source proposal submitted by netproject, another consultancy.
Leslie Burr, Capgemini executive consultant, told the press conference that "open-source software has more security issues" than Microsoft's software.
"We established that Microsoft had invested considerable time and energy into the security of their systems," Burr said.
Given the torrent of viruses, worms and Trojans that are taking advantage of security vulnerabilities in Windows, it is surprising to hear Microsoft billed as a particularly secure choice.
Many of these pieces of malware use holes in Internet Explorer. Steel, though, didn't accept that he'd sleep better at night if Newham Council was using Mozilla, the open-source browser.
"I have technical people to worry about that," said Steel.