Update: 15 March 4.02pm
The issue with Gmail and Google Drive was resolved by Google.

Original Update: 14 March 4.16pm
We are aware of an issue that is affecting usage of Gmail and Google Drive. Users are able to access both, but may be seeing error messages and other unexpected behaviour. This is an international issue that Google are currently working to resolve. We will provide updated information as we receive it however, you can check the status of the issue here