The report, which says devolution means Wales has shed its image of being England's "backyard with coal tips", will not now be published until September. However, similar reports for other regions of Britain have already been published.
Geoff Martin, head of EC representations in the UK, said: "It was drawn to my attention that there were what were described as tonal difficulties with the Welsh report and I am making an assessment with my colleagues in Brussels. As a result, we have now decided to hold off until the autumn.''
The report was to have been one of a series outlining how each region of the UK has benefited from European spending.
It is not clear who initiated the delay in publishing the Welsh report. Jan Royall, who works for Neil Kinnock, the EU Transport Commissioner, said: "I was in discussion with various people but I am not prepared to go into this any further."
The unpublished Welsh report states: "Wales approaches the millennium with a new-found confidence, the enduring impression that it is England's backyard with coal tips finally banished by the reality of a democratic, economic and environmental transformation that has established the region as one of the most attractive in Europe for inward investment.''
The report's author, John Humphries, former award- winning editor of the Western Mail, said: "I have been told that at the eleventh hour, as the elections campaigns were getting under way, and four months after I had completed the report, that objections had been raised on the grounds that its tone was too nationalistic. Now today they are talking about inaccuracies, but they have had the document for more than four months and it has not been raised before."Reuse content