As PRWeek went to press, frontrunner David Miliband was understood to have already acquired a domain name and developed a campaign site.
Labour insiders also said Miliband had lined up leading figures in the political blogosphere to implement an ambitious social media strategy.
Alex Smith, editor of the LabourList blog, and Jessica Asato, outgoing acting director of progress, were both said to be on Miliband's radar. Smith declined to comment, while Asato said she was not working for any campaign
No candidates had been declared as PRWeek went to press.