The chancellor has said she was having a “tough day” yesterday in her first public comments since appearing tearful at Prime Minister’s Questions – but insisted she is “totally” up for the job.

Rachel Reeves told broadcasters: “Clearly I was upset yesterday and everyone could see that. It was a personal issue and I’m not going to go into the details of that.

“My job as chancellor at 12 o’clock on a Wednesday is to be at PMQs next to the prime minister, supporting the government, and that’s what I tried to do.

“I guess the thing that maybe is a bit different between my job and many of your viewers’ is that when I’m having a tough day it’s on the telly and most people don’t have to deal with that.”

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She declined to give a reason behind the tears, saying “it was a personal issue” and “it wouldn’t be right” to divulge it.

“People saw I was upset, but that was yesterday. Today’s a new day and I’m just cracking on with the job,” she added.

Ms Reeves also said she is “totally” up for the job of chancellor, saying: “This is the job that I’ve always wanted to do. I’m proud of what I’ve delivered as chancellor.”

Asked if she was surprised that Sir Keir Starmer did not back her more strongly during PMQs, she reiterated that she and the prime minister are a “team”, saying: “We fought the election together, we changed the Labour Party together so that we could be in the position to return to power, and over the past year, we’ve worked in lockstep together.”

PM: ‘I was last to appreciate’ that Reeves was crying

The chancellor’s comments come after the prime minister told Sky News’ political editor Beth Rigby that he “didn’t appreciate” that she was crying behind him at Prime Minister’s Questions yesterday because the weekly sessions are “pretty wild”, which is why he did not offer her any support while in the chamber.

He added: “It wasn’t just yesterday – no prime minister ever has had side conversations during PMQs. It does happen in other debates when there’s a bit more time, but in PMQs, it is bang, bang, bang. That’s what it was yesterday.

“And therefore, I was probably the last to appreciate anything else going on in the chamber, and that’s just a straightforward human explanation, common sense explanation.”

During PMQs, Tory leader Kemi Badenoch branded the chancellor the “human shield” for the prime minister’s “incompetence” just hours after he was forced to perform a humiliating U-turn over his controversial welfare bill, leaving a “black hole” in the public finances.

The prime minister’s watered-down Universal Credit and Personal Independent Payment Bill was backed by a majority of 75 in a tense vote on Tuesday evening – but a total of 49 Labour MPs voted against the bill, which was the largest rebellion in a prime minister’s first year in office since 47 MPs voted against Tony Blair’s lone parent benefit in 1997, according to Professor Phil Cowley from Queen Mary University.

Ms Reeves has borne a lot of the criticism over the handling of the vote, with some MPs believing that her strict approach to fiscal rules has meant she has approached the ballooning welfare bill from the standpoint of trying to make savings, rather than getting people into work.

Ms Badenoch also said the chancellor looked “absolutely miserable”, and questioned whether she would remain in post until the next election.

Sir Keir did not explicitly say that she will, and Ms Badenoch interjected to say: “How awful for the chancellor that he couldn’t confirm that she would stay in place.”

Downing Street scrambled to make clear to journalists that Ms Reeves was “going nowhere”, and the prime minister has since stated publicly that she will remain as chancellor “for many years to come”.