Oracle has accused European competition authorities of cherry-picking comments from a market survey to support objections to the firm's planned acquisition of Sun Microsystems.
Representatives of the enterprise software company are attending a two-day hearing in Brussels to win European approval to close the $7.4bn deal to acquire Sun.
European competition authorities say that Oracle's control over Sun's open source MySQL database could harm competition in the database market.
But yesterday Oracle said "many if not most" of the customers cited in the commission's statement of objections do not support the EC's theory of harm, according to the Financial Times.
Oracle also accused EC officials of ignoring the views of some of the biggest customers, including General Electric, Fujitsu, Siemens and Nasdaq.
EC commissioners are concerned that Oracle will not support and develop MySQL in future, but Oracle argued that the EC needs show that this is the "most likely outcome" to justify its objections.
Oracle claims it plans to increase the research and development budget for MySQL and has marshalled some top customers for support.
EC commissioners will also hear opposing views from SAP, Microsoft and MySQL founder Monty Widenius.
Commission officials, however, have indicated they are hopeful the concerns can be overcome by reaching an agreement on what conditions to attach to the deal.
If the hearing fails to quash the EC's concerns, commissioners have until 27 January to reach a final decision.