The Foreign Secretary, David Miliband, has become the first senior Labour figure to call on the party to follow the Conservatives and allow the public to select parliamentary candidates in primary elections.
In an article for the left-wing magazine Tribune, Miliband argues that primaries should be explored at a time when membership -based political parties are "close to death".
He said: "We say we want to listen to our voters; why not a system of registered voters as in the US to create the basis for primaries?"
Interest in primary elections has been stimulated by the Conservatives who allowed the public to select their candidate for the Totnes constituency. The party sent out ballots to all 69,000 Totnes voters and saw 16,497 people elect GP Dr Sarah Wollaston as the new candidate.
In his piece Miliband also points to the example of the Greek socialist party, PASOK, who hold open primaries and who were one of the few centre-left parties to make gains in the recent European elections.
"The party has quotas for male and female representation, open primaries to select party candidates for local elections and has developed Every Day a Citizen, an organisation dedicated to citizen engagement," said Miliband.
"Such engaging and deliberative party structures enable PASOK to tap into the energy in communities and multiply the force of a national message through local, authentic, committed advocacy, with resultant electoral success."
But critics of primaries argue that opening internal party elections to the public will hasten the decline in party membership, depriving parties of subscription fees.
Figures released by the Electoral Commission last week showed that Labour membership fell to 166,000 in 2008, down from 176,891 in 2007. Influential party figures including Jon Cruddas, the MP for Dagenham, have warned that the party faces oblivion unless it arrests the decline in membership, which has fallen from a peak of 405,000 in 1997.
