Health ministers have been warned that people could stop giving blood if they believe private firms will profit from their goodwill.
Lib Dem MP Annette Brooke said voluntary donations of blood and organs could be “put at risk” by plans to overhaul the NHS blood service.
The government is carrying out a review into the future of NHS Blood and Transplant to explore how further savings can be made.
This could mean more of its support activities are outsourced, but ministers have insisted the service will remain in the public sector and no parts will be sold off.
At Commons question time, Mrs Brooke (Mid Dorset and N Poole) asked: “I wonder if you could give further assurances to address the very great concerns that voluntary donations of blood and organs could be put at risk if it’s perceived that profits are being made in any part of the operation?”
Junior health minister Anne Milton replied: “The altruistic donor system is one of the rocks that the NHS is built on and we will not do anything to jeopardise public confidence in it.
“I’m a bit alarmed at some of the scare stories that have been circulating and they serve nobody any good, least of all those who need the necessary donations that are made.”
The government has received 60 representations on the future of the blood service from MPs, unions, and the public since February, Ms Milton added.
“The current review has not been considering the sale of any part of NHSBT,” she said.