After 10 years leading the quantitative division he set up, Edmonds will now take overall responsibility for the management and expansion of the entire London operation.
The quantitative division accounts for more than a third of the agency's business.
Edmonds masterminded 2CV's integrated research product alongside founder Vincent Nolan.
He will now head up the UK management team to provide advanced research services for established clients including COI, ITV, Nokia and EA.
Blandford will manage the rollout of the 2CV global network, following the recent launch of 2CV North America, which was the first stage of the agency's international expansion plans.
He will be responsible for driving the creation of local hubs in major business centres across the globe as well as managing strategic UK acquisitions.
2CV said that the appointments follow a 26% increase in sales from 2007 to 2008 and head count growth of 21% in the UK and 150% in the US, with both offices still actively recruiting.
Vincent Nolan, founder of 2CV, said: "Appointing a 'numbers' man as MD underscores the importance we place on delivering integrated and commercially meaningful research.
"With turnover increasing rapidly, we've now set our sights on further accelerating growth internationally, with his exceptional business development track record."