The figures come from data collected in December 2015, with London North West as the worst offender.
“We have also forged close links with the London Ambulance Service to better manage the demand to ensure patient safety at all times.”
London North West also missed the target for 85% of patients on the urgent cancer route starting treatment within 62 days of referral, at 82.4%, and has missed the target every month since it switched to being published monthly.
More patients attending A&E
A spokesperson said: “We’re working in conjunction with Hillingdon CCG to improve pathways within A&E and increase GP availability out of hours”.
Across England, 91.8% of patients on the waiting list at the end of December 2015 had been waiting fewer than 18 weeks.
This is the first time the 92% standard has not been met since it was introduced in April 2012, showing a nationwide change, with 755 patients waiting more than 52 weeks at the end of December 2015.
Despite this, A&E attendances have dropped on a national level with 1,867,657 attendances at A&E in December 2015, 1.8% less than in December 2014.
Overall, 91% of patients were admitted, transferred or discharged from A&E within four hours of arrival, which is below the 95% standard but higher than the same month last year.