The shadow health and social care minister has said it is "wrong" for Matt Hancock to endorse private companies, such as the app GP at Hand.
Appearing on the breakfast show, Labour MP Justin Madders said it was "really not appropriate" for the health secretary to be "advancing the interest" of a private company while the NHS continues to struggle.
"To be seen to be favouring individual companies is really not appropriate," Mr Madders told talkRADIO's Daisy McAndrew.
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Hancock came under fire after appearing in an advertorial spread for Babylon's health app GP at Hand, with some GP surgeries displaying posters in waiting rooms urging their patients not to use the app.
"He [Hancock] appeared in the Evening Standard last year in what was described as an advertorial, talking about one of these particular companies and I think that showed pretty poor judgement."
Labour MP Justin Madders. Image: UK Parliament
Mr Madders appearance on the show followed calls for Matt Hancock to stop private companies from securing NHS contracts.
"The roots of this go back to the Health and Social Care Act of 2012, which put a requirement on NHS trusts to tender out to the private sector," Mr Madders explained. "We've always said that this is a wasteful process."
"Actually, it doesn't always deliver the best results," he added.
The issue is expected to be debated in the House of Commons later today.