Negligible value claim

I hold some SEIS shares, original cost £2,900, now valued at £290. I'm aware that the interpretation of negligible is "next to nothing" but this is still pretty subjective. Could a 10% value be deemed as negligible ?

Hi

Negligible value claims must be submitted in writing or by entering a negligible value on your tax return.  
For tax purposes there is no accepted definition of ‘negligible value’, but generally it applies to assets that have become worth next to nothing while someone has owned them.  
Assets cannot have been of negligible value when you acquired them, they must have become of negligible value while you have owned them.  
If you can give evidence to HMRC that shows that your assets no longer have any value since you acquired them, you may be able to make a negligible value claim.
You can use this to realise a loss to reduce your Capital Gains Tax liability. Please see Negligible value claims and agreements

Thank you