The DEA 2010 was passed through Parliament by the previous Labour government. It included provisions to warn individuals caught illegally downloading that they faced being cut off from their ISP - and to stop filesharing sites benefitting from Google Ads.
However, the Act has since been disputed in the courts by the likes of BT and TalkTalk, whilst Ofcom's guidelines on how the DEA would work in practice are yet to be published. The group said last year that 'three strikes' letters now weren't likely to be sent out until 2013 at the earliest.
"I think they've been dragging their feet - this discussion has been going on long enough," Harman told Music Week today, following a speech to students at the University Of Hertfordshire.
"Every day they don't implement the Digital Economy Act, thousands of pounds is being lost, and money made illegally. There's a good possibility to get the advertising revenues [on filesharing sites] choked off and for the Government to deal with that. These illegal websites are not doing this from the goodness of their heart - they're making money. The point is to stop their source of funds."
Earlier, Harman told students that the Government needed to "strike the right balance between the content industries, including music, and the technology companies to create a climate where innovation can flourish while copyright is protected".
She added: "This debate has been going on for long enough and needs to be brought to a conclusion... The Government should implement the Digital Economy Act under a clear timetable including getting on with the notification letters and publishing the code of practice. They should also lead and set a deadline for agreement in the industry for site blocking, search engine responsibility and digital advertising. The music industry - and other creative industries - say that if the government got a move-on, they could do this by May this year. [The Coalition needs to] make it clear that if there's no agreement, this will be legislated for in the Communications Bill."
Discussing Google's role in helping copyright holders curb online piracy, Harman added:
"The technology companies need to do more with the content creators to better signpost legitimate search. And they should do more to tackle piracy including by stifling the income of the pirate websites. There are a relatively small number of very big pirate websites which make a lot of money. When they are based offshore they are hard to reach. But that mustn't lead us to conclude that nothing can be done. Google, as a major site for advertising, could take a lead to engage the advertising industry in depriving illegal sites of their advertising revenue.
"If Google and the ad agencies drain the swamp of piracy by removing their financial incentive - online advertising - then we would have a fertile environment in which paid-for content could flourish.
"No-one could imagine how we would survive without Google - many of us use it hundreds of times a day. But it is because they are so effective - and trusted - that Google and other search engines should use their creative energy to help the music industry fight piracy."