Deduction of Union Fund from wages of non-union employees after wage settlement

We have recently arrived at a settlement with the Union on their COD. Similar benefits have been extended to the non-union employees as well. The Union is insisting that certain portion of the wage increment so arrived must be paid to the union fund from both the union employees and also from the non-union members. Remitting the wage increment of the Union employees to the Union fund is understandable, but should a similar payment be done by non-union employees also? The Union has quoted the Hon'ble Supreme Court decision in Blemeri workman case reported in 1985 LLJ in support of their demand. I request the IR experts and knowledgeable HR professionals in this forum to throw light on this matter.
Thank you.
Ramesh Nambiar

Dear Mr. Ramesh,
As per narrated facts, you may collect concent from employees through union in writing or membership record then you can make deductions otherwise no.
The facts of the said case are not matching with your case. This is a very sensitive matter, please handle with care and all precautions.
Regards,