'No major piece of legislation passed since 1997 has changed so radically between White Paper and Royal Assent as the Gambling Act, and this is due in no small part to this campaign,' the judges concluded.
The campaign was also praised for its mix of public affairs and PR techniques, use of research and 'tightly targeted' press releases. The way messages were tied to key stages of the legislation process was also cited as a crucial factor in its success.
Culture Secretary Tessa Jowell said: 'I think we will have better legislation because of the campaign they have led.'
The RNID's 'Don't lose the music' campaign was highly commended for targeting 18 to 30-year-olds with its warning that listening to loud music can damage health.
Other shortlisted campaigns included those by The Stroke Association, Breast Cancer Care and Refuge. The National Lottery's tenth birthday campaign, run by Euro RSCG Biss Lancaster, also made the shortlist.