The size of the country's waiting list has been described as "stomach-churning" by The Royal College of Surgeons which warned it will take years to clear.
NHS statistics show 40,658 patients were listed as waiting for elective operations or treatment at United Lincolnshire Hospitals NHS Trust at the end of March, up from 39,366 at the end of February.
It was also up from 38,105 the year before, and the highest figure for the month of March since comparable records began in 2012.
NHS rules state that patients referred for non-urgent treatments under the care of a consultant should start treatment within 18 weeks.
But the figures also show 1,877 patients on waiting lists at United Lincolnshire Hospitals Trust at the end of March had been waiting for at least a year – five percent of all those on the waiting list.
Across England, the number of people waiting to start hospital treatment rose to 4.95 million – the highest total since records began in August 2007.
The Royal College of Surgeons said the task ahead for NHS workers was vast following an "unimaginably difficult year".
Vice president Tim Mitchell said: “With the number of Covid-19 patients in hospital at the lowest it has been since September last year, the recovery of planned surgery is fortunately now well underway.
"Still, any prospect of chiselling down the waiting list, which is now 5 million people, is premature, because new patients are presenting daily.
"The task ahead is vast and many of the staff that support surgeons to operate, anaesthetists and nurses, are running on fumes after an unimaginably difficult year helping out on Covid-19 wards.”
Money will be given to hospitals for mobile scanning trucks, carry out surgery in evenings and at weekends and to provide "virtual wards" where patients can be continually monitored while outside hospital.
Amanda Pritchard, NHS chief operating officer, said: "The additional support announced today will help us create a blueprint for continuing that progress over summer and beyond, in a way that doesn’t heap extra pressure on staff, so that as many people as possible benefit from the world-class care the NHS provides.”
The investment has been welcomed by the NHS Confederation, which represents organisations in the health service.
But Danny Mortimer, chief executive of the body, said there were "bigger, bolder" moves the Government needed like providing more capital funding to NHS trusts to take to help with demand.