More than 45,000 people have signed a petition calling for the family of a girl from East Sussex to be allowed into the UK to attend her funeral.
Five-year-old Andrea Gada, of Downland Close in Eastbourne, was hit by a car on 16 December and died in hospital the following day.
Her grandparents and aunt were refused visas to come to the UK from Zimbabwe.
Liberal Democrat MP Stephen Lloyd raised the matter during Prime Minister’s Questions on 14 January.
David Cameron said he would look at the case and make sure the Home Office investigated what could be done.
Setting up the petition calling for the visas to be granted, Andrea’s mother, Charity Gada wrote: “My beautiful five year old daughter, Andrea, was killed just before Christmas.
“An unbearable time has been made even worse as the Home Office refuses to give my only living relatives visas to attend the funeral.”
She said her relatives were being denied access to the UK because they were “too poor”. The Home Office told Mr Lloyd it stood by the refusal because the family members do not meet the requirements of the immigration rules.
Mrs Gada said: “My family are street sellers from Zimbabwe. They pose no risk to the country, they simply want to support us and grieve the loss of our beautiful girl.”