Serena: My colleague, Alan, has a slightly different take. Here’s his reply:
I’d argue against making this a separate contract, i.e. a separate employment. This might make it look like she has not returned from her maternity leave, i.e. quit which will affect her ability to claim EI in the future. However, there does need to be a written agreement that clearly indicates the failure to return to her existing position was at the employee’s request and that what she is asking for is a phased return to her old position. I’d rather emphasize that this is a bridge between the leave and her return, rather than a standalone new employment contract.
And I don’t see that a change in position or title necessarily leads to a new employment contract. It might mean a change in the terms and conditions of employment, but not a separate period of employment. If you treat the phased return as its own period of employment, then there will have to be another when the person finally does return to her old duties.
But your advice to consult a knowledgeable lawyer is also good.
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Glenn again: Hope this helps and do talk to a lawyer before deciding what to do.