Campbell claimed the idea of what One Nation Labour is was "not established" and "means to the public whatever the public wants it to mean".
The One Nation slogan was first used by Ed Miliband at the 2012 party conference, where he stated that it represented: "A country where everyone has a stake; a country where prosperity is fairly shared; where we have a shared destiny, a sense of shared endeavour and a common life that we lead together."
His words follow shortly after Labour MP Simon Danczuk told PRWeek that the party had to move away from "political mantras".
In December a leaked memo revealed that Campbell, who was one of the key figures behind New Labour and No 10 director of comms between 1997 and 2003, would be drafted in to help Labour’s election efforts.
Campbell, now a part-time consultant at Portland, warned that the party needed at least four "hard-hitting" policies if the public was to understand what One Nation Labour stood for.
Referring to Ed Miliband’s speech at the Labour Party Conference, he said: "One Nation worked last year for Ed’s speech but it wasn’t followed through with a hard-hitting policy."
The four policies would include "one on the economy, a couple on public services and one about cultural space".
Campbell added that the idea of nationalising railways was one "that people can latch on to, and should be explored further".