In a note to JLR staff on Monday, the company said the "foundational work of our recovery programme is firmly underway", and the phased restart was to ensure IT systems were brought back in a "safe and secure manner".
Previously, the company had said it did not expect production to resume at its facilities until 1 October at the earliest.
The spokesperson said JLR was continuing work on its recovery following the shutdown.
"We continue to work around the clock alongside cybersecurity specialists, the UK government's National Cyber Security Centre and law enforcement to ensure our restart is done in a safe and secure manner," they said.
