Police are searching for the 35-year-old from the Newcastle area after a mother and two children were doused with an alkaline substance in Clapham, south London on Wednesday night.
The mother, 31, remains sedated in hospital, and is said to be “very poorly” with “life-changing” injuries.
Her daughters, aged three and eight, the youngest of which was allegedly thrown to the ground in the attack, are said to have suffered less severe injuries.
