Does the Information Commissioner recommend that GP Practices rely on consent for GDPR purposes?

No.

The Information Commisioner says

“Consent is one lawful basis for processing, but there are alternatives. Consent is not inherently better or more important than these alternatives. If consent is difficult, you should consider using an alternative.

Consent is appropriate if you can offer people real choice and control over how you use their data, and want to build their trust and engagement. But if you cannot offer a genuine choice, consent is not appropriate. If you would still process the personal data without consent, asking for consent is misleading and inherently unfair.

If you make consent a precondition of a service, it is unlikely to be the most appropriate lawful basis.

Public authorities, employers and other organisations in a position of power over individuals should avoid relying on consent unless they are confident they can demonstrate it is freely given.