Hundreds of striking Heathrow workers will be on the picket line outside Heathrow Airport today.
It involves workers in separate pay disputes with Wilson James and OCS.
They will hold a joint picket line outside the airport on Nene Road from 10:00 to 13:00 today.
It is not expected to cause disruption to airport operations or flights.
Around 500 Heathrow Wilson James workers provide assistance to passengers with restricted mobility while another 50 workers employed by OCS as British Airways cleaners are taking strike action.
The Wilson James workers claim they are paid considerably less than their colleagues at London Gatwick performing the same role.
The OCS workers are also striking over pay.
The company is accredited by the Living Wage Foundation for paying its directly employed staff a real living wage.
However OCS’ BA workers are being paid the minimum wage union Unite says.
Both companies reported healthy multi-million pound profits in the last financial year, the union said.
Unite general secretary Sharon Graham said: “Heathrow, Wilson James, BA and OCS are all highly profitable and can more than afford to ensure these workers are offered reasonable pay deals.”
The Wilson James workers are striking today only after postponing earlier strike action on to ballot on a revised offer from the company.
This offer was rejected and further industrial action will now be scheduled.
The OCS workers took industrial action in February and March with the latest round of action lasting from 8 to 23 April.
