Dawn Butler, the Labour deputy leader candidate, has revealed she is mistaken for other black female colleagues “at least once a week” and described her “exhausting battle” to be correctly identified, after the BBC confused her with fellow MP Marsha de Cordova earlier this month.

The senior Labour MP, who was the first black woman to speak at the dispatch box in 2009, said she had been becoming “immune” to being mixed up with colleagues, but felt it necessary to speak out this time because she did not want newer MPs to suffer the same misidentification.

In an interview with the Guardian, Butler said: “It’s exhausting to constantly fight that battle, or constantly have to justify your presence in a space. When it happens to me, sometimes I can ignore it. But I felt the other week that actually I have a responsibility to all of the African Caribbean women coming in behind me. So I take that responsibility seriously, and that’s why I was so willing to call it out.”

Butler criticised the BBC over the incident and then subsequently De Cordova was confused with another black Labour MP, Bell Ribeiro-Addy in the Evening Standard, which the newspaper blamed on its picture agency.

Butler, who is pitching to be the first black person in a Labour leadership role, said it was crucial for media organisations to correct their biases by being extra vigilant against mistakes.

“You know what: we all have biases,” she said. “That is how we navigate our world, through certain lenses. But if you haven’t got anybody in the room who can identify Dawn Butler as different from Marsha de Cordova, then you need to have somebody in the room who can, so you need to make that adjustment … It was not about making a mistake, it is about making an effort.”

Butler has previously spoken of racist incidents in parliament in which she was asked to get out of an MPs’ lift because she was assumed to be a cleaner and another in which a police officer had to apologise after escorting her out of the MPs’ tearoom.

She said she had a habit of reciting the words from Labi Siffre’s Something Inside so Strong at meetings, hustings, and even in the House of Commons because it had previously been her private theme tune to say to herself whenever she was entering a hostile room.

“Sometimes I will stand in the doorway of the room, and I will own the room before I walk in it,” she said. “So that when people are attacking me, or when people are dismissive of the fact that I am an MP or dismissive of the fact that I’ve earned my right to be in the room, I know I’ve already owned the room so that they’re less likely to undermine who I am. My dad was a musician and so my politics comes from music. And I think every resistance movement, every uprising, has its own soundtrack.”

She said as a black woman in politics: “I am judged more harshly and suffer more racial abuse because I am black and because I am a woman and because I don’t just hide away in a corner and not say anything when I’m being racially abused.”

She said it was “shocking, but it’s not surprising” that Labour had not had a black person in a leadership position before “because there’s been so few minority MPs”. But she said this should change given the influx of black, Asian and minority ethnic MPs in the last few years.

Butler said she had thought about standing for the leadership because of encouragement from colleagues but felt her campaign would have lagged behind because she had not prepared.

She also hit out at the structure of the leadership campaign, saying it favoured wealthy candidates and put those from working class backgrounds at a disadvantage.

“It is stressful and expensive. I am completely overdrawn because you have to fund everything yourself,” she said. “The system itself is weighted against people who are working class and who haven’t got the trade union backing or family with money – which is bad for the Labour party.”

She said candidates had to fund their own travel and hotel when going round the country to persuade local parties to back them, and suggested Labour should help bear the cost to even the playing field.

Butler made it through the second round by gaining the support of more than 70 local parties but suggested the whole process should be streamlined to just put candidates straight to a vote of the membership.

Asked if she would scrap the 2018 reforms to the process that introduced new hurdles, she said: “Granted, this could be kind of biased because I’m in the midst of it right now, but yes, 100% I would scrap this process. And I do think that if as MPs we are committed enough and brave enough to put ourselves forward, then the members should just decide.”

Butler is considered on the left of the party but has won support from local parties in combination with all of the different leadership candidates from Rebecca Long-Bailey to Lisa Nandy.

In terms of her views on the deputy role, she said a reorganisation of party structures was needed to give regions more independence, more technology in campaigning and Labour MPs should be clear that if they defect to another party, they must resign their seat.

Referring to MPs who left the Labour party partly over Corbyn’s leadership, she said: “If we have MPs who have decided that they are going to resign because they don’t like who the members have selected [as leader], they should be subject to a byelection. It’ll be a contract of employment almost.”

However, she stopped short of endorsing Long-Bailey’s call for open selection of MPs, meaning they effectively have to reapply for their jobs at every election.

She said she would like a citizens’ assembly-style group to consider it but said careful attention must be paid to whether such a “system that may discriminate against women or black Asian minority ethnic people”.

Her very strong pro-trans rights position during the contest has caused some criticism from commentators, including her assertion that children are not born with a biological sex. But Butler said of the debate overall that she was sure there was “a way that we can talk through the issues and come to a solution in a way that ensures everybody’s rights are protected – not trans women’s rights against other women’s rights”.

“We also have to be mindful that attacks against trans women have gone up exponentially over the last three years because of the Gender Recognition Act and so this is not an anti--women agenda. This is a pro-women agenda and our battles are not with each other.”

The deputy leadership candidate defended the party’s 2019 manifesto, while acknowledging it had too many policies like a “Toby Carvery” where too much is piled on the plate at once. And she warned that Labour must be careful in its position on Brexit and attempts to win back northern heartlands not to neglect its London and other metropolitan heartlands at the same time.

“I had somebody say to me, Dawn, I want you to be deputy leader because you visibly represent some of Labour’s heartlands,” she said. “And we often feel during the debate, that we are invisible and that we don’t matter. And that our vote’s being taken for granted.’ So we have to be careful that we don’t ignore other bits of Labour’s heartlands. Because people can vote when they want to vote. And when somebody said that to me … I thought, yeah, it’s true.”