who is responible for garden fence on the left of rear garden

[dickulas]

who is responsible for garden fence on left

[CheekyChops]

It depends what the deeds to your house say. There is no definate rule.

[buildersmate]

Must be at least 2 months since we answered this question. Sounds like time for it to come around again.

[heathfield]

Usually, it's whoever erected it in the first place, or thereafter, the successors to the property.

[spudqueen]

I'll just reiterate that you need to look at your deeds. At our first house we owned the fence on the left, at our second house we owned the fence on the right and in our current house all boundaries are jointly owned!

[buildersmate]

If your land is registered at the Land Registry the Title Plan may show a series of the letter T against the fence lines. If the Ts are on your side you own the fence. If your land is unregistered, your deeds may show a similar annotation.
If you have no Ts and nothing else describes any ownership you will have to discuss the situation with the neighbour and agree who is going to do what.
If you can't agree, the safest way for you is to leave the existing fence in place and put your own new fence inside the line of the existing.
If you can agree, then you could replace the existing fence, or you could agree to share the cost.