If you are on gardening leave you have to be available for work each day you might normally have worked whilst you are being paid.

If they know what you are going to be doing, they may do this to sabotage your plans.

If they pay you off with pay in lieu of notice, your employment finishes when they pay you.
You can then work for yourself or anyone else immediately.

They only have to pay YOU 7 weeks if that's your notice period.
Wait for a week after the others, then put your notice in.

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