Tips for tightening basin backnut?

[copea]

I need to fit a set of taps where the tap tail has a 1/2" feed to the central mixer off to the side, as per the diagram below:

I obviously need to tighten the backnut to the basin, but the side projection makes the box spanner that I have totally useless.
The adjustable and non-adjustable basin wrenches and regular wrenches I have also foul on the feed or the ceramic of the basin.

I'm running out of ideas. Anyone got any suggestions?

I'm going to pick up a couple of split klick centralising washers from Toolstation this morning as I figure they may make up for some of the slack that I can't take up, but other than that I think I'm just going to have to do the best I can do with the tools that I have.

Any other ideas welcome.
Thanks!

 

[rsgaz]

Anyone got any suggestions?

Would you be able to get a crowsfoot spanner in there? Maybe on one or two wobble extension bars to get the angle you need.

 

[oilhead]

Try googling Duckfoot or Crowfoot wrench.They are available for 1/2 and 3/4 double ended and should allow you to pinch up a hand tightened tap before making the rest of your connections.

 

[copea]

Thanks gents, was wondering whether such a thing existed, but not knowing its proper name it makes searching/asking for it difficult.