If accepted, can I still sell my property?

Yes of course.

You can either pass on the opportunity to your property buyer – so we will then deal with them (and they will get the payment when the value uplifts)

OR

You can divide the land you are selling from the rest of the property, sell the house and smaller garden,  and continue to deal with us about the excess garden. Note that in this case,  you can’t claim the PPR tax relief because you are no longer living at the property, so there may be some Capital Gains Tax to pay.