Routine hospital appointments are to be deferred to help hospitals combat severe winter pressures, health officials have announced.
In a drastic step to try to free up hospital staff and beds, NHS England had also said that the deferral of non-urgent elective care - such as hip or knee replacements - should be extended until at least the end of the month.
Meanwhile, to free up doctors to care for patients with urgent need, day-case procedures and routine outpatient appointments should also be deferred until January 31, officials said.
This will mean that senior hospital doctors can triage more patients in A&E, be available for phone advice for GPs and ensure that patients in hospitals are reviewed twice each day to help timely discharges.
NHS England also said sanctions for mixed sex accommodation breaches should be temporarily lifted.
Men and women are supposed to be treated on different wards under NHS rules.
Officials started collecting data on the practice in 2010 in a bid to crackdown on the number of men and women treated on the same wards.
Trusts could be fined for breaching the rules.
But sanctions have now been suspended, NHS England confirmed.
The measures from the health body were announced following a meeting of its National Emergency Pressures Panel, chaired by Professor Sir Bruce Keogh.
In a statement, NHS England said that the panel discussed "sustained pressure over the Christmas period" with high levels of respiratory illness, high bed occupancy levels, signs of increased flu activity and a rise in the number of severe cases attending A&E.
The measures outlined could also help by freeing up time for physiotherapists for speedier discharge from hospital.
Sir Bruce, NHS England national medical director, said: "I want to thank NHS staff who have worked incredibly hard under sustained pressure to take care of patients over the Christmas.
"The NHS needs to take further action to increase capacity and minimise disruptive last minute cancellations. That is why we are making these further recommendations."
NHS England reiterated that cancer operations and time-critical procedures should go ahead as planned.