At the front of our house there is a long and steep bankside. The bankside is classed as highway and doesn’t belong to us, but there is shared path running up the bankside that services my neighbours house and ours.

The path is getting quite old now and could do with some repair, but who would pick up the cost of this – us or the Highways Dept?

We’ve always cut the grass and kept it tidy, but the path could cost a fair bit to repair.

Report it to Highways and see what happens.
Personally, I think it sounds like their responsibility anyway. The angle of the bank should have nothing to do with it.
If it were a grass verge with a dropped kerb providing access to your driveway it would be their responsibility.

The bankside is classed as highway and doesn’t belong to us, but there is shared path running up the bankside that services my neighbours house and ours.

If this an access servitude then there should be something in your deeds that will describe how the maintenance cost are to be apportioned. If this is the case then I would have thought that it would be split between all the properties that are serviced by the path.

Have a word with the council highways dept, It might be theirs but it could just be other council land, green spaces or some dept like that.

As a rule of thumb if the land/slope is retaining the highway, the highway boundary is usually at the bottom of the slope. If the highway is lower than your house the highway boundary will usually be at the the back of the footway or 0.5m (ish) from the edge of the highway, if no footway.

Check your deeds, if you have them, but contact the council to see who has responsibility for the land.

I assume we’re talking about council highways rather than Highways Agency major A road type thing?