A woman whose son died of Deep Vein Thrombosis (DVT) after a flight to Benidorm, will find out if she is eligible to claim compensation.
Brenda Wilson began campaigning after her son's death in 2001
The House of Lords is to rule on whether relatives of victims of DVT can take legal action against airlines.
Brenda Wilson, from Wigan, Greater Manchester, began campaigning for victims of DVT after the death of her 32-year-old son, Neil, in January 2001.
DVT can be caused by sitting in cramped conditions for long periods of time.
The Appeal Court ruled that the victims or their families could not sue airline companies over DVT last year.
But now the case has gone to the House of Lords, which must decide whether blood clots linked to flying could be deemed an accident.
British Airways said on Monday it would not be pursuing legal costs even if the Lords rules in its favour, rejecting the relatives claims.