A man who brought his baby niece to Britain in the back of his car from a French refugee camp after she sustained serious burns has had his deportation halted at the last minute by the Home Office.

Najat Ibrahim Ismail, 32, an Iraqi Kurd with a British wife and three young British children, was prosecuted for trafficking after he brought Rwen Tahsin Ibrahim, then seven months old, and other family members to the UK in January 2016 in what he says was an attempt to save the child’s life.

Following his criminal conviction for bringing the girl to the UK, he was due to be deported to Iraq on Tuesday afternoon. However, Home Office officials told his lawyers the deportation has been deferred. No explanation was provided for this U-turn.

Speaking from Harmondsworth immigration removal centre near Heathrow, Ismail told the Guardian: “I was so happy when I was told that I would not be getting on the plane today. All I want is to be freed from detention so I can be back with my wife and kids.”

When he found out in January 2016 that Rwen had been badly burned after falling into an open fire, Ismail travelled to Grande-Synthe refugee camp in Dunkirk, where his brother Tahsin Ibrahim was living with his family after fleeing Islamic State in Iraq.

He wanted to get the baby medical treatment in the UK, away from the filthy conditions in the camp. Although she received initial hospital treatment in Dunkirk for her burns, her family feared she was at risk of life-threatening infection after being discharged because the conditions in the camp were unsanitary.

The relatives Ismail brought into the UK used false travel documents they had acquired from a smuggler in the camp.

When Ismail arrived at Portsmouth ferry port with his relatives, he was arrested. He was later charged and convicted of trafficking-related offences for bringing his relatives to the UK, and sentenced to 24 months in jail. The judge criticised him for planning the offence, but said: “I do accept that you were not a person who was trafficking for gain. These were family members you decided to assist.”

Under Home Office rules, any foreign national who has served a sentence of more than 12 months is automatically liable for deportation, although “compelling circumstances” are considered.

Ismail’s brother’s family were granted refugee status in the UK. Rwen received treatment in the UK and has made a good recovery.

Ismail arrived in the UK in 2004 after fleeing torture in Iraq. He was granted indefinite leave to remain in the UK and lives in Portsmouth with his British wife, Emma, and their three young children.

Ismail’s solicitor, Hannah Baynes from Duncan Lewis, said: “We are very pleased to hear that our client’s removal to Iraq today has been deferred. We know that this has been an incredibly distressing time for him and we continue to be concerned about the impact of being in immigration detention on his mental health.

“We will now consider the appropriate steps to ensure that [he] is released from detention as soon as possible so that he can be reunited with his wife and children.”

Chai Patel, the legal policy cirector for the Joint Council for the Welfare of Immigrants, said: “Najat is neither a trafficker, nor a criminal for trying to save his baby niece’s life. We would all want to help our families if they were in the same position.

“Our laws clearly do not reflect the morals and values of our country, and we must make sure no one is punished like this again for trying to do the right thing by their family.”

A Home Office spokesman declined to comment on the last-minute deferral.