I know this sort of thing crops up here periodically, so hope I can tap
into the group's expertise...

My neighbour apparently has a blocked pipe (sewage? surface water? not
sure yet); however this affects me in that said pipe runs under my drive
where it mates up with an inspection cover (from where DynoRod are doing
their stuff). I don't have any drainage problem myself, but if the
damage/blockage is on the leg of pipe just serving the neighbour's
property, but is located on my property, do I need to share (bear?) any
repair costs?

Or is this one of those 'check the deeds' questions?

Relations are good and I don't want to shirk any responsibilities I may
have, but don't want to offer something I don't need to!

Thanks
David