Mr. Burnham and Ms Merron spent time at Lincoln's Healthy Hub in Beaumont Fee before visiting the new endoscopy unit at Lincoln County Hospital.
The paper asked Mr. Burnham about the former chief executive of United Lincolnshire Hospitals Trust, Mr. Gary Walker, who claims the Government's obsession with targets is jeopardising patient safety.
Mr. Walker was sacked following a row with NHS East Midlands over missed targets and is now standing against Ms Merron as an independent candidate in the General Election.
Mr. Burnham said:
"Targets are essentially about people as they are about minimum standards that every patient and their family should be able to expect when they arrive at the door of the NHS.
"I believe the NHS needs national standards and the majority of NHS organisations around the country are achieving these and I believe everyone should.
"I don't place targets above patient safetySpeaking to Ms. Merron on Guildhall Street in the City Centre yesterday Ms Merron indicated she thought she was in with a chance of keeping the seat, based on her record of hard work for the constituency.
"It was not safe in the old days to have people waiting in A&E for seven, eight or nine hours and nor was it safe to wait for hospital operations for months on end."