You have until Friday to accept WhatsApp's new privacy policy or find a new online messaging service.

That's the message from its owner, Facebook, which is pushing ahead with its move to share more information from WhatsApp users with its main social network.

But users and government agencies are objecting to the changes, and it's not clear who will ultimately succeed.

WhatsApp's controversial privacy changes sparked a user exodus in January, causing downloads of its major rival, Signal, to spike by more than 4200 per cent.

The backlash also saw Facebook extend the deadline for users' acceptance of the conditions from February until May 15, though WhatsApp now regularly serves users reminders.

Changes to WhatsApp's terms of service are designed to share more information about WhatsApp users with Facebook and its "family of companies".

The new terms state Facebook "may use the information we receive from them, and they may use the information we share with them, to help operate, provide, improve, understand, customise, support, and market our services and their offerings".

The content of WhatsApp messages will not be made available to the tech giant, thanks to end-to-end encryption, but the app could share metadata to expose who you're talking to and your location.

But concerns about the changes have not only been raised by users but by some government agencies.

Brazilian authorities, including its data protection agency ANPD, last week asked Facebook to delay its deadline while concerns about its privacy policy were addressed.

And a German data regulator is seeking an "administrative order" to stop the changes, amid concerns it could be "an abusive exploitation of data power".

Facebook has yet to back away from the changes, though it has softened its stance to those who refuse to accept the new terms.

In an update, WhatsApp said no user would have their account "deleted or lose functionality" on May 15, but warned users would eventually lose access to WhatsApp features like their chat list and would not be able to "receive incoming calls and notifications" if they ignored warnings to accept the new policy.

Originally published as Aussie WhatsApp users to hand over more data or lose features