A van driver has admitted killing two young children and seriously injuring their mother in a motorway crash as the family returned from a birthday party. Martin Newman, 41, pleaded guilty to causing the deaths by dangerous driving of Jayden-Lee Lucas, three, and his four-year-old sister, Gracie-Ann Wheaton. He also admitted seriously injuring their mother, Rhiannon Lucas, in the crash on the M4 at 1.45pm on Saturday 5 February. The family, from Tredegar in Blaenau Gwent, south Wales, had been returning from a birthday party when the car they were travelling in collided with Newman’s Ford Transit on the motorway between junctions 28 and 29 near Newport. Newman, of Croeserw, a village near Port Talbot, spoke only to confirm his identity and enter his guilty pleas during a brief hearing at Cardiff crown court on Monday. Few details of the offence were given and Judge Daniel Williams listed the case for sentence on 8 April. Several of the children’s relatives were in the public gallery, and one person yelled “bastard” as Newman was led from the dock. The two children were taken to the intensive care unit at University hospital of Wales in Cardiff after the crash. Lucas and the children’s father, who has not been named, were also taken to hospital. Gracie-Ann suffered a cardiac arrest due to the severity of her injuries and died the next day at about 5am. Jayden-Lee died the following Friday at 4.30pm. In a tribute to Jayden-Lee, his cousin, Jamie Lucas, 19, said: “He was wonderful, creative and a kind soul. Turned the grey skies blue.” Of Gracie-Ann, he said: “She was so young. She had a bright future ahead of her. She was such a wonderful child. She was very smart, she was very creative. She had a really great imagination as well. She was just fantastic to be around.” A GoFundMe page set up to raise money for the siblings’ funeral has raised more than £14,700. Huw Waythe, the headteacher of Deighton primary school in Tredegar, described them as two “special children”. He said: “Our thoughts remain with members of the family, and words cannot adequately express the shock and pain which they must be feeling. “We are shocked and saddened by the loss of two of our own. We will never forget how special the children were to our school community. “They both put a smile on all our faces daily. They were a delight to have and both always lit up any room with their positive personality and beaming smiles.”