A research report by the umbrella body's Compact Advocacy Programme - published on the eve of Compact Week, which runs from 1-7 November - criticises the Government department for persistently ignoring the six-year-old agreement between the state and sector, which is meant to ensure proper consultation and fair treatment.
The NCVO says that the DCMS pressed ahead with the lottery merger despite direct opposition from the voluntary sector.
The breaches included announcing the merger in February 2003 when a 2002 consultation on the future of the lottery had not addressed the specific issue of whether the Community Fund and New Opportunities Fund should merge. Then, in an answer to a Parliamentary question from Tory MP John Whittingdale, Secretary of State Tessa Jowell did not mention that the NCVO and many other voluntary organisations had registered their opposition to any merger of the lottery distributors in the 2002 consultation (Third Sector, 12 March 2003).
The DCMS finally announced a three-month consultation on the merger in March 2003, under pressure from the sector.
But the report says: "The concern remained that they would not actually be consulting on whether the merger should take place, but merely on the details of how it should be implemented.
"In other words, the decision to merge had been made without consulting the sector most affected."
The NCVO also claims that Jowell's department is still not paying heed to the Compact. In August, the Secretary of State announced funding outcomes and priorities for the new Big Lottery Fund halfway through the fund's own consultation with the sector.
The NCVO's chief executive, Stuart Etherington, said the report "reflects the views, experiences and opinions of our members who work with the DCMS".
But a spokesman for the department condemned it as unbalanced: "The Compact makes a virtue of transparency and consultation. Sadly, neither features strongly in the preparation of this report," he said. "We are surprised and disappointed that the report has so little to say about the many areas in which there has been fruitful co-operation and good practice."
Among the recommendations made by the report are that staff induction and training programmes in the DCMS and affiliate bodies should promote awareness of the Compact.