The NHS in Oxfordshire and nationally is experiencing huge challenges as Covid-19 rates communities continue to rise.
The number of COVID-19 positive patients requiring hospital treatment in Banbury and Oxford and Banbury has increased significantly in recent weeks.
Staff are currently caring for twice the number of Covid-19 positive patients than at the peak of the first wave of coronavirus in Spring 2020.leading to pressures on beds on wards and in intensive care, operating theatres and staffing levels.
"We are redeploying some staff to work in areas where Covid-19 positive patients are being treated and working closely with our partners in the Oxfordshire health and care system and further afield," the Oxford University Hospitals Trust (OUH) said in a statement.
"In order to meet this challenge, we are focusing on urgent and emergency care for both Covid and non-Covid patients, as well as urgent cancer care.
"We are postponing all routine inpatient and day case elective surgery on all of our hospital sites. We are still admitting patients in need of urgent surgery that cannot be delayed, including cancer patients."
Where possible, the trust's outpatient clinics are continuing in Banbury and Oxford and in the community but capacity is reduced so there will be unavoidable postponements of some outpatient appointments.
The trust will continue to see urgent referrals and 2 Week Wait cancer referrals. Its diagnostic services are currently operating as normal.
GPs are being asked to refer patients to OUH in the usual way as hospitals are not closed to GP referrals.
Sara Randall, Chief Operating Officer at Oxford University Hospitals, said: "These measures are necessary so that our staff can prioritise the care of the sickest patients and maintain safe patient care during this unprecedented time for the NHS both locally and nationally.
"We appreciate how frustrating this will be for patients affected and we would like to apologise to them. We know that many people waiting for treatment will be disappointed or worried, and we are contacting everyone affected.
"We have not taken this decision lightly and would like to reassure our patients that we are taking all necessary steps to try to keep any disruption to an absolute minimum.
"We would like to thank our communities for your support and understanding at this hugely challenging time."
Patients affected will be contacted as soon as the trust is able to reschedule their planned surgery - patients will be rescheduled according to clinical need and length of wait.
Sam Foster, Chief Nursing Officer at Oxford University Hospitals, said: "Please help us to help you by following the lockdown rules in order to protect your local NHS, choose the right healthcare service for your needs and help us to support your loved ones when they're ready for discharge from hospital."