The number of patients waiting more than six months for NHS surgery has risen by 180% in the last four years, a new study suggests.
The number of people waiting 26 weeks rose to 126,188 in March, up from a low of 45,054 in March 2013, research by the Royal College of Surgeons (RCS) found.
Its president, Clare Marx, accused all the political parties of having "a blind spot" over the issue and called for more attention to be paid to the issue by whoever wins the General Election.
She said: "Waiting times have come down a lot since 10 years ago and far fewer patients are waiting over a year for treatment.
"However, over the last few years waits for treatment have begun to head in the wrong direction once again.
"We are now struggling to meet the standards and timeliness of care that the public rightly expect.
"It is unacceptable for such a large number of patients to be waiting over half a year in pain and discomfort for treatment.
"This is the grim reality of the financial pressures facing the NHS."
The study found that surgical disciplines with the biggest increase in waiting times in the last four years were ear, nose and throat (up 256%), urology (199%), general surgery (146%), oral surgery (146%) and brain and spinal surgery (145%).
Its analysis also found that the number of patients waiting more than nine months for surgery rose 209% in the same four-year period, from 6,415 patients in March 2013 to 19,838 patients in March 2017.
Miss Marx added: "Many of these patients are older and in the most serious cases, such as for brain surgery, waiting longer could have a big effect on the quality of someone's life and their eventual recovery from surgery.
"With the 18-week target now being deprioritised, our concern is that we will see a fast deterioration in waiting times with tens of thousands of more patients waiting longer than six months for surgery."
NHS England declined to respond directly to the six-month figures.
A spokeswoman said: "Actually the NHS has cut the number of patients waiting more than a year for treatment by nearly 13,000 over the past five years, and spending on non-urgent surgery is continuing to rise.
"While the Royal College of Surgeons understandably lobbies for more spending on surgeons, in the real world they aren't the only call on constrained NHS funding, which also has to support extra investment in GP services, modern cancer treatments, and expanded mental health services."