A woman threatened to knife a baby on a packed Tube train after the 15-month-old kicked her from her pram, a court has heard.

Millicent Barnes, 22, is accused of screaming abuse at Geraldine Brannigan and demanding her daughter “apologise” – despite the fact the child was only just learning to speak.

Barnes, from the Lindley Estate in Peckham, allegedly became aggressive towards Ms Brannigan and her family when they boarded the Central Line on July 18 this year at around 5.30pm when the train was packed with rush hour commuters.

City of London Magistrates’ Court heard that Ms Brannigan and seven other relatives had been out to celebrate her brother’s graduation and that it was so packed on the train that she and her mother had boarded at one end of the carriage, while her father – who was pushing the pram – and other relatives got on at the other.

As they got on Ms Brannigan’s baby kicked Barnes from her buggy, prompting Barnes to start shouting and demanding an apology from “it”.

Giving evidence from behind a screen, Ms Brannigan said at first all she could hear was raised voices from other family members saying “she’s kicked the buggy”.

She said she heard a female voice shouting she wanted “it” to apologise and by the time she managed to squeeze to the other end of the carriage, Barnes was leaning into the buggy shouting.

“[My daughter] is a well behaved little girl, she doesn’t kick or punch, she was just sitting there like a normal child. She doesn’t do anything out of the ordinary,” she said.

She continued: “Perhaps not the best choice of words, but my mum said ‘shut your mouth, you’re scaring the child’.”

Ms Brannigan said she initially thought Barnes was mentally unwell or on drugs because she was so loud and aggressive.

Barnes allegedly said to Ms Brannigan’s mother: “Don’t tell me to shut my f***ing mouth – you’re an old lady and you’ll have a f***ing heart attack. You don’t want to know what I have in my bag.”

Ms Brannigan said: “She said she didn’t give a f*** about the child and she’ll stab it.”

She added: “It felt like it was becoming a life or death situation. You don’t deal with things like this every day so I felt vulnerable for my daughter.”

The complainant said she pulled out her phone to try to call the police but that she started filming when she realised she had no signal.

Ms Brannigan said Barnes kept trying to push her hands away to prevent her getting a clear shot.

“She was shouting ‘record me, record me, I don’t give a f*** about the police, record me’ – there was no reasoning with this individual,” Ms Brannigan said.

“My daughter was screaming now – fortunately a member of the public jumped in saying ‘You need to stop, the child is scared’.”

She said a male who was with Barnes told her: “She doesn’t give a f*** about the child and she’ll stab it.”

He then said: “All you need to do is get the child to apologise.”

“I explained to him she can’t say sorry, she’s too small,” Ms Brannigan said.

She continued: “At this point [the defendant] is still ranting and raving – she makes a comment that she is going to stab the child and makes a suggestion that she’s going to go into her bag – whether she was just scaremongering I don’t know.”

Ms Brannigan said that when the train stopped at St Paul’s station she yelled from the train to people on the platform “she’s going to stab my child”.

“I just stood there instead of being a good parent and grabbing [Barnes], I don’t know why I didn’t,” she said.

The complainant said a member of staff helped her and her family get off at St Paul’s but that Barnes was trying to spit at them as they left.

“In my opinion that’s the lowest thing you can do,” she said.

Barnes was tracked down after the British Transport Police released images of her alleged tirade against the Brannigan family.

Fellow passenger Chantelle Wilson tried to intervene on behalf of Ms Brannigan, the court heard, and she attempted to pull the hood of the buggy down to protect the baby from the commotion.

She said she asked Barnes “to have some respect” for the child, and that the man who was with her did nothing to try and calm her down.

Ms Wilson said: “The [defendant] shouted I’ve got a knife in my bag.”

She added: “She then said ‘She’s got a knife in her bag’, but not to anyone in particular.”

When the train pulled into St Paul’s she said she told station staff they needed to call the police, telling them there was a woman with a knife.

“As the doors were closing – literally as they closed, a member of station staff said ‘there is no police’,” she said.

“I’m now stuck on a train with a woman who’s got a knife in a bag, she’s now speaking to me and says ‘was I talking to you’.”

Ms Wilson said Barnes had got close to her and was thrusting her breasts against her arm.

“She was doing it deliberately to try and intimidate me – I said ‘get your hand out of my face’, she replied ‘get your face out of my hand’,” she said.

She continued: “I said ‘get your breasts off my arm’, she responded ‘just because I’ve got some, your just jealous’.

“She was trying to intimidate me and succeeding, she’s saying she’s got a knife in her bag and that bag was near me.

“I’m thinking at that point ‘am I going to get home to my children?’.”

Barnes denies one count of using threatening words or behaviour with intent to cause alarm or distress.

The trial, which is scheduled to last for one day, continues.