More than 23,000 died in A&E in England last year, figures obtained by Labour show.
The opposition party has released data it obtained through freedom of information requests, which shows an increase in deaths compared to previous years.
The Royal College of Emergency Medicine previously said 23,000 “excess patient deaths” may have occurred partly due to A&E delays in England in 2022.
Data provided by NHS trusts to Labour shows a total of 23,316 lives were lost in emergency departments.
This is around 4,000 more than 2021, and 5,500 more than 2019.
NHS targets say 95% of people in A&E should be seen within four hours. Labour claims this target has not been hit since 2015.
Shadow health secretary Wes Streeting said: “People turning to the NHS in an emergency should know they will be seen and treated before it’s too late. The Conservatives’ failure over 13 years to properly staff or reform the NHS has a cost in lives.
“When Labour was last in government, patients in an emergency were treated in good time.
“It took 13 years for the Conservatives to break the NHS, it won’t be fixed overnight. But it will be the mission of the next Labour government to build an NHS that is there for you when you need it once again.”
Prime Minister Rishi Sunak has made tackling NHS waiting lists one of his five priorities, although this also refers to elective procedure waiting lists.
Health minister Maria Caulfield said: “The uncomfortable truth is where Labour are in power, the NHS is worse.
“In Wales, Labour have consistently failed to meet waiting targets since their introduction 14 years ago and caused higher excess death rates than in England.
“Meanwhile, we are delivering a record number of tests, speeding up discharge from hospitals, and cutting waiting lists as we also work to halve inflation, grow the economy, reduce debt and stop the boats.”