Lily Allen claims she was told to "find an immigrant" by a taxi driver who refused her a lift - days after she apologised to migrants in Calais on behalf of Britain.
Following a visit to the Calais "Jungle", the singer broke down in tears last week having spoken to an Afghan teenager who claimed his father was living in Birmingham while remained trapped in the camp.
Allen, 31, was then criticised after issuing an apology on behalf of the UK for what it had 'put migrants through'.
On Friday, Allen, daughter of actor Keith Allen, said she had been refused a ride in a black cab - the driver of whom allegedly told her to "find an immigrant" driver.
Taking to Twitter, The Fear singer said she had been with her daughters when she was shunned by the cab.
The driver even allegedly referred to her as a "tart".
Allen said the incident had given her a "glimpse of what it feels like to be discriminated against".
After describing the event over social media, Allen encouraged her follows to "stamp out this stupid ignorance altogether".
Some people responded to Allen's tweets claiming the incident "definitely didn't happen", prompting the singer to respond that they were "victim shaming" her.
She later added that London cabbies were the "best in the world".
Last week, Allen told the Afghanistani boy: "It just seems that at three different intervals in this young boy's life, the English in particular have put you in danger.
"We've bombed your country, put you in the hands of the Taliban and now put you in danger of risking your life to get into our country.
"I apologise on behalf of my country. I'm sorry for what we have put you through".