Thanks for your enquiry.
There is no automatic right for your Landlord to forfeit a lease unless the lease contains specific provisions by way of a clause setting out the grounds on which the landlord may forfeit.Most Leases have a suitable clause stating that if the Rent is unpaid for a period of 14 or 21 days, then the Landlord does have a right to forfeit the Lease. You therefore need to check the wording of your Lease to clarify this.
If there is such a clause, which is likely, he landlord's actions must indicate that he intends to end the lease, so actions to the contrary, like accepting rent, will remove his right to forfeit.
Therefore, if your Landlord does accept part or all of the rent arrears from you in the next couple of days, then he loses the right to forfeit the Lease.
It is therefore very much up to the Landlord as to whether he is just trying to claw back the rent arrears from you or whether he is determined to forfeit the Lease, as to whether he would accept such payment from you.
Subject to the above working out for you, a Landlord would allow you to sell/assign the Lease provided there are no rent arrears at the time, and he was happy with the financial viability of your Buyer.
I hope this answers your question, and if so, I would be grateful if you could leave positive feedback.