Stella Creasy has urged the Labour Party to reject "tribalism" as the criticism of different views smacks of a "cult" and the "thought police".
The Labour deputy leader contender has also told The Huffington Post UK the party will need to have a "long hard look" at how it champions equality if men are returned as both leader and deputy leader.
Polls suggest Jeremy Corbyn as leader and Tom Watson as deputy is the most likely outcome as its stands.
In a wide-ranging interview, the Walthamstow MP argues voters have become "disconnected" as the Party acts like a "machine", and would devote the deputy role to being more "collaborative" with the grassroots.
Her comments come amid fierce rows between factions of the party amid the soaring poll rating of left-wing leadership contender Jeremy Corbyn.
While Mr Corbyn's policies have been criticised by moderates led by Tony Blair, the left-wing of the party and activists on social media have labelled the centrist candidates as "Tories".
Creasy makes a call to reason, arguing: "Clem Attlee said the Labour party is what the members make of it. That's all of us.
"What I would want to do as deputy is make sure everyone felt responsible and accountable. That includes Tony Blair, that includes Jeremy Corbyn, that includes Len McCluskey. No more shouting from the sidelines.
"Thinking that everyone has to think the same is the mistake people make. That's being a cult. It’s not being a political party, it’s the thought police.
"People have been tweeting me for having the temerity to be a member of lots of different organisations because obviously I must think the same as everyone."
She adds: "We can't afford to keep being tribal."
Creasy, an outspoken feminist, was also concerned about the party's claim to be leading the fight on equality. She says it is not good enough only one in four party members in parts of the country are women, and if two men are fronting Labour that is "part of the wider problem".
She said: "Most of my adult life you have had two men running the Labour Party and nobody has said anything about it at all. Two women and everyone’s like 'oh'.
"It speaks to the bigger issue. In an election where the majority of candidates are women, if we end up with two blokes? Labour needs to take a long hard look at how equality is best manifested.
"What I'm saying is that's not just an issue at the top, when we've got local parties in that state as well, it’s an issue for everywhere. For the party that brought in all women short-lists and the Equal Pay Act, equality is not here. And if we act as if it is we have a big problem."