The walkout started at 7am on 16 September and was due to continue until 7am on 18 September, as workers demand the same one-off payments already awarded to their NHS colleagues.

Unison says the wage deal agreed for NHS staff on Agenda for Change contracts in June 2023 included two lump sum payments for the 2022/23 financial year, but Serco has refused to pass on the one-off bonuses - worth at least £1,655 - to its employees at Great Western Hospital.

Jayne Jackson, Unison South West regional manager, said: 'Serco's refusal to honour the NHS pay deal is deeply unjust and has left hard-working hospital staff struggling to make ends meet.

'Serco posted profits of over £249m in 2023, so there's no justification for denying its employees the same financial recognition as NHS workers. Staff have been left with no choice but to strike to demand the fair pay they're entitled to.'

In response, a spokesperson for Great Western Hospitals NHS Foundation Trust, said 59 Serco company staff working in housekeeping and portering at the Great Western Hospital had voted for industrial action.

They added: 'While the pay dispute is between Serco and Unison, the trust is working closely with Serco to ensure the impact of the strike action on service and care delivery remains minimal.

'We do not anticipate any disruption to patient care, and all patients should attend their appointments as normal.'