Heathrow Express rail services face disruption on Sunday and Monday as drivers and other staff go on strike.
Members of the Rail, Maritime and Transport (RMT) union plan to walk out for 24 hours from 12:15 GMT on Sunday.
The dispute, involving up to 250 staff, follows the sacking of a driver and the suspension of a union representative.
Heathrow Express, which will run an amended service, said it was disappointed the action was going ahead and apologised to passengers.
It said the suspended employee had returned to work and the driver had been dismissed fairly.
Industrial action
- 24-hour strike from 1215 GMT on 26 February
- No extra hours worked over 3-4 March weekend
- 24-hour strike from 1215 GMT on 11 March
A second 24-hour stoppage is due to start from the same time on 11 March, while union members will not work any extra hours over the weekend of 3-4 March.
The action is in support of sacked driver Zahid Majid and the suspension of Liaqat Ali.
Mr Majid was dismissed after a minor error, for which he took full responsibility.
In the case of Mr Ali, the RMT said he had been subjected to “unfounded, spurious and discriminatory allegations”.
The union’s general secretary Bob Crow said: “The unfair and disproportionate punishment taken by management in both these cases is a total miscarriage of justice.”
A spokeswoman for Heathrow Express said it hoped union members would recognise the employee had been dismissed fairly in accordance with union policy.
BBC
