Hi Molmeister ---- The only reason for this indemnity cover is to cover the buyers of your property against any chance of the back payments being demanded all of a sudden by the deceased landlords successors.
At the moment according to contract the most they could be backcharged for is 7 years at £5 = £35 in total after you move out, this is the maximum amount that you would be liable for, so I cannot see why they would not take a deposit of £35 off you to cover this risk on your behalf without you needing this expensive policy.
Once you've sold it the new owners would be liable for the £5 annual charge anyway, so that should be arranged by them and in fact the policy would not cover them for future ground rent anyway.
This policy could be deemed as mis-sold because it's going to cost £140 when the maximum it could be of benefit is £35 which is absolutely ludicrous. !!!
You could make a written offer to stand this yourself out of your own back pocket, if they use common sense they would accept that. ????
These policies and the need for them has really gone over the top nowadays.
PS -- Smiley button is in,"options" when you write a post or edit one..