The event was listed on Virgin Healthcare’s website as being held at Manchester’s Imperial War Museum and is one of 16 events being held across the country.
Virgin Healthcare was officially launched at the beginning of the year to provide services in partnership with existing GP surgeries.
A message on the website added: ‘GPs and their practice teams are invited to attend one of our twenty-six events being held across the country in February and March where we will explain our plans in more detail.’
A Unison spokesperson said: "We are absolutely opposed to the move by Virgin Group into GP surgeries. It is deeply alarming that a private company such as Virgin Group will be marketing its additional services to potentially vulnerable patients when they are in need of medical care as if they were visiting a gym.. . . We should not allow health centres to be run by gym managers."