Prospecting is when charities pay agency fundraisers to approach members of the public on the street and ask them to sign up to lobbying campaigns before phoning them to ask for donations.
The housing and homelessness charity said its in-house fundraising team had tested the technique over several years on private sites such as festivals before deciding to hold a national campaign.
"We are happy with the results and we know it works," said Matt Goody, head of direct marketing at Shelter.
"One problem with contacting people by phone later is that you can reach only some of them, but we reached about 700 out of every 1,000 names we collected, and a significant proportion of them signed up to regular giving."
Shelter's campaign calls on the Government to pay for an extra 20,000 social rented homes to be built every year as part of the 2007 Comprehensive Spending Review.
The Public Fundraising Regulatory Association has begun discussions with its members on developing a voluntary code of practice for prospecting, amid concern that the method could be confused with face-to-face fundraising.
Oxfam began using the technique as part of its I'm In anti-poverty campaign. Both Oxfam and Shelter said they would be happy to sign up to a scheme that regulated prospecting.
"We are open to the idea of self-regulation," said a spokeswoman for Oxfam.