Fbr Ireland

For the last three years I have been trying to obtain a fbr Ireland my grandfather was Irish however my mother was born in Brussels and has since lost her birth certificate I have applied to all the provinces in Brussels to obtain a copy with no luck.I have everything else required including my mother’s marriage certificate with my grandfather named on it.
I am worn out now and am hoping someone on here could help me ,do you think I should submit application minus mother’s birth certificate with an accompanying letter even though they state not to do this?I have wrote to Irish mp’s along with Belgium mp’s but didn’t get a response thanks in advance for any help

I can't see how you would be approved without proof of Irish lineage which is what that birth certificate shows. Is the difficulty with replacing your mother's birth certificate that she doesn't know where in Belgium she was born? A quick search on google mentioned needing to show up in person with all the appropriate documentation to have a birth certificate recreated. But I'm assuming that would be difficult if you don't know which municipality she was born in. Have you hired a professional genealogist to see what they can turn up? If you exhaust all possibilities you could hire an attorney to draft an affidavit with all the facts supported by documentation of lineage along with proof of your exhaustive attempts to find the record and then take your chances with an application. The good thing is that time is on your side, since the processing time seems to be heading toward 2 years I suppose you could always submit with the affidavit and continue to look for the birth certificate and then submit it if/when you find it. It'll be a gamble but you've got nothing to lose other than the application fee I guess.