80GGC - Politically party donation not consider by Employer

Hello Tax gurus,

I have mode some donation to political party under section 80GGC.

But My employer is not accepting that Donation saying that it is not listed in "DEDUCTION OF TAX AT SOURCE- INCOME-TAX DEDUCTION FROM SALARIES UNDER SECTION 192 "

Please guide is there any such rule to not accepting 80GGC donation by employer ?

Thank you 

Prakash