Some routine appointments at Kingston Hospital could be cancelled and 999 calls for minor illnesses may not receive an ambulance response during today’s strike action.

Nurses, hospital porters, midwives and cleaners are among Unison members who voted to take part in the coordinated day of action protesting about changes to public sector pensions.

The hospital said most services would be running today, and it had been working with unions to minimise disruption to patients.

A spokesman for Kingston Hospital NHS Trust said: “We have business continuity plans in place to ensure our emergency services such as A&E and emergency surgery will be running as usual.

“We will be monitoring the impact of the strike throughout the day. If services are affected more than anticipated there may be some short notice cancellations to some planned outpatient appointments and other routine appointments, such as X-rays, which will then be rearranged.

“We will contact patients directly on the day if their appointment is affected. We will also update our website regularly regarding affected services; otherwise patients should assume their appointment is going ahead.”

A spokesman for the ambulance service said: “As ever, we will prioritise our response so our most seriously ill and injured patients get help quickly, but some people, who are not in a life-threatening condition, may have to wait longer than normal for an ambulance response.

“Although our staff will be answering all 999 calls, some patients with minor illnesses or injuries – such as back pain, upset stomachs or small cuts and bruises – might not receive an ambulance response. Instead, they will be given advice on how to look after themselves or told where else to seek help.

“Whilst we have arrangements for staff to provide emergency cover, we do expect our service to be under pressure and we would urge people to only call 999 in a genuine emergency.”

Meanwhile, Kingston police confirmed officers would be deployed at a march through the town centre by strikers, but expected the demonstration to be peaceful.

A spokesman for the Metropolitan Police said it had contingencies in place for the absence of the civilian staff who are members of the striking Public and Commercial Services Union.