So the car has been slowly dripping diesel on the new tarmac drive for a couple of months and cos of where it is and it being winter I didn't notice it. Car is fixed now, so no more drips.

So anybody know the best way to deal with it? I'm rather wary of using any type of detergent as it may affect the tarmac, same goes for using some cement dust.

Any thoughts people?

Kitty litter? Sand or something like that?

Jasper, problem with diesel is that it destroys the binding agent - hence them resurfacing roads after diesel spills (and before anyone says it - yes it also reduces the co-efficient of adhesion).
Can you not dig out the offending patch and replace with fresh tarmac?
You'll probably need a pick to remove it (watch out for hidden services though) and then a tamper or heavy metal plate (locost solution) to achieve a good finish.
IIRC you can buy bags of patching tarmac from B&Q.
HTH.
Cheers, Pewe10

What is it you're trying to fix? Just a stain or has it dissolved the tarmac?

Hi leave it alone we used to spray diesal onto plannigs and wack it and stood up for years you cannot get the diesal back of and there are no lorrys turning etc will be ok for years

Thanks chaps - just spoke to the guy who laid it, he said the same, leave it alone and he'll come and replace it when he has a bit of spare.