Rotten wood holding bath tap

[Hammer]

It looks like that over time water has got under the seal of the bath tap and has rotted away at the wood that effectively holds the taps steady on the bath. Obviously the tap is no longer steady and water continues to get under the seal. The wood itself is sealed to the bath, I'm guessing with some form of adhesive.
You can see in the picture that plastic nut (?) appears corroded (it should be black like the one on the right) and it's sunk into the wood which is particularly rotten (see white area to left of the tap in question).
All advice and top tips to get a stable tap welcomed. Thanks.

 

[moonlight]

If you can reach the rotton wood, Isolate water supply take the tap out and nibble the wood away. Put a new piece in with a hole for the tap. Refit tap making sure you fit correctly and if necessary apply silicone under the base of the tap before pushing through hole. Remake joints. Water back on, sorted.

 

[snowhead]

The non Black plastic nut will clean up.

 

[Ben-gee]

I have got over this problem by simply cutting a “large washer” from wallboard. I drilled a hole for the tap to pass though . If you don’t have enough space between the backnut and the tap connector (wallboard is 11mm thick) you could do the same with a thin metal plate

 

[Hammer]

If you can reach the rotton wood, Isolate water supply take the tap out and nibble the wood away. Put a new piece in with a hole for the tap. Refit tap making sure you fit correctly and if necessary apply silicone under the base of the tap before pushing through hole. Remake joints. Water back on, sorted.

Thanks Moonlight. Much appreciated.

 

[Hammer]

I have got over this problem by simply cutting a “large washer” from wallboard. I drilled a hole for the tap to pass though . If you don’t have enough space between the backnut and the tap connector (wallboard is 11mm thick) you could do the same with a thin metal plate

Ben-gee: builds on advice from moonlight. Gives me more confidence to crack on and get it sorted. Thanks.