Labour deputy leadership candidate Caroline Flint has warned that Corbynmania on social media may not be reflective of real life.
In an interview with BuzzFeed News – conducted on Monday before a YouGov poll predicted a landslide victory for Corbyn – Flint insisted that most Labour members are not on Twitter or attending leadership rallies.
The shadow energy secretary said: "There's been a lot of press coverage about it [Corbynmania] and a lot of people turning up at the hustings. But actually in terms of the whole membership, it's only a fraction of the people who actually have been turning up at the events who will be taking part.
"And also most of our party members, to be honest, aren't on social media and Twitter. So I think there's a danger in this for all of us who are candidates in either the leader or deputy leadership race to somehow think that Twitter in itself is telling us what's really happening. I prefer to see what the true result is at the end of the day.
"But it's a big decision for the party because it's not only about who ticks their boxes but who has that appeal to the country and who can help us get back to a place where we can win the next general election."
Corbyn, a veteran left-wing MP and serial rebel, is now the bookies' clear favourite in the leadership race after starting as the 200-1 outsider. Flint, who served in ministerial posts under Tony Blair and Gordon Brown, said she would work as deputy under any candidate as long as they proved they could lead Labour to power.
"I've been on a few protest marches in my time and they have their place," she said. "But for all the protest marches we had in the '80s and in the last five years, the truth is that when we came to the election we didn't have enough to offer those working-class and middle-class people who are neither rich nor on benefits, who go out to work and felt that we weren't speaking to them."
Flint also warned it would be "terrible" for Labour if two men ended up as leader and deputy.
"I'd like to see a gender balance at the very least," she said. "I'm not coming out for anyone for the leader position but, for me, I do want to see a woman Labour leader in my lifetime. I've been in the party 36 years, I hope it's not going to take another 36 years to get there.
"If the end result was two women, that, in my book, would not be a bad result, but I wouldn't want to see two men at the top of the party."
Labour had always had to "deal" with the fact that the Tories had the first woman prime minister, Flint added. "The sad thing about Margaret Thatcher during her time in office was that she didn't lead the way to encourage more women within her own party to take senior roles," she said.
"So this is also about what we can do as women to encourage other women to get involved in politics, become councillors, become MPs, and not have a 'queen bee' effect in politics. That's not my style of leadership."
Five MPs are running to be deputy leader – Flint, Tom Watson, Ben Bradshaw, Stella Creasy and Angela Eagle – while four are standing as leader: Corbyn, Andy Burnham, Yvette Cooper and Liz Kendall. Ballot papers will be sent out on Friday, with results announced on 12 September.