It would depend on the circumstances.
For what reasons are you leaving the employment? Redundancy? Retirement?
Will you be seeking an alternative full time position?
If it’s redundancy for example, you would need to be sure it doesn’t affect your redundancy entitlements.
If you’re seeking alternative work, you would need to be confident it doesn’t conflict with the terms of employment of any new position.
Is it intended that the arrangement be casual/ad hoc or would it be provided for in some sort of contractual agreement?
Without knowing the specifics, my feeling is that you would still be an employee, albeit in much different terms and conditions. This might affect your redundancy entitlement.
The alternative to employee status is that you’re akin to a contractor, with all that that entails.