If the IRCC or CBSA believe you made a misrepresentation at anytime during your citizenship application process, your application may be refused. A misrepresentation need not be intentional, and could even be the result of a typo in an application. 

The drastic consequences of a misrepresentation finding means you need to be extremely vigilant in filling out the paperwork, not just in an honest way, but in a way that IRCC will believe to be true, and where there are not even the most minor of errors that could get you flagged for misrepresentation. 

It may be possible to appeal an inadmissibility finding due to misrepresentation to the Immigration Appeal Division of the Immigration and Refugee Board, or seek judicial review to the Federal Court.