Legal aid has been granted for Shamima Begum – who joined the Islamic State group aged 15 – to fight the decision to revoke her UK citizenship.
The 19-year-old, who left east London in 2015, was stripped of her citizenship in February, after she was found in a Syrian refugee camp.
Her family has previously said it planned to challenge the decision.
Foreign Secretary Jeremy Hunt said the Legal Aid Agency’s decision to assist Ms Begum made him “very uncomfortable”.
He added, however, that the UK was “a country that believes that people with limited means should have access to the resources of the state if they want to challenge the decisions the state has made about them”.
Legal aid is financial assistance provided by the taxpayer to those unable to afford legal representation themselves, whether they are accused of a crime or a victim who seeks the help of a lawyer through the court process.