A union activist and G4S employee is fighting attempts by immigration officials to deport his wife to South Africa next week.
GMB branch secretary in west London Derek Rawlings and his wife Kalpana have come up against a "catalogue of official failures" in their battle to persuade immigration officials to let her stay in Britain.
The couple have won the backing of GMB, which has called for a review of complex regulations and laws which the union says "cause confusion and harm families."
Even in the House of Lords there has been bafflement over Britain's immigration regulations, which Mr Rawlings says have changed almost 100 times since 1994.
Ms Rawlings is due to be deported on January 8 and they have now written to Prime Minister David Cameron asking him to intervene.
The couple have lived in Britain since they married in December 2009 and Ms Rawlings was granted leave to remain as his wife from May 2010 to May 2012.
When leave to remain expired she applied for permission to stay "as the spouse of a person present and settled in the UK" and the application was put through the UK Border Agency's (UKBA) system.
But it hit problems over payment of a standard fee and use of a bank card sent to the UK Borders Agency by the couple.
The UKBA said the Rawlings' bank had rejected the card but the bank has denied this.
A series of exchanges took place but the end result is that the Home Office have refused Ms Rawlings permission to stay and the couple face being broken up.
GMB general secretary Paul Kenny said: "Derek's account of the catalogue of official failures that have led to the threat to deport Kalpana is truly shocking.
"It appears that we are in danger of our frequently changed immigration laws splitting the family apart. The ceaseless changes are making the law incomprehensible."
The couple await a reply from the Prime Minister's office.
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