Elzbieta Olszewska, 80, had been living alone in her flat in Warsaw before arriving in the UK last September. Her only child, Michal Olszewski, 52, an aeronautical engineer who lives in Lincoln with his wife, had been travelling regularly to the Polish capital to support her.

Olszewski has been living in the UK since 2006, initially as a EU citizen. He subsequently became a British citizen and has dual Polish-UK nationality. As his mother has become increasingly frail he wanted her to move to the UK so he and his wife could care for her properly. There is a legal route under the settlement scheme for people in Olszewski’s situation to bring parents to the UK.

Olszewska arrived in the UK last September on a six-month visitor visa and shortly afterwards the application, containing all the correct information, was made for her to live permanently in Britain with her son and his wife. Until a few days ago the family had heard nothing from the Home Office although the application had been lodged in good time before the six-month visa expired.

But on 25 March the Home Office finally responded, informing the family: “Unfortunately your application is not valid and we are unable to accept it.”

The rejection letter went on to say: “The required application process for someone applying as a family member of a relevant naturalised British citizen is to use the appropriate paper form. Your application was made online. There is no right of appeal in respect of an invalid application.”