2 job offers - on employment pass

Hi,

I am on a P1 Employment Pass earning SG$130k per annum. I got a job offer from Company A last month (May) and as such have resigned from my current firm. Company A has confirmed that an In-Principal Approval has been done for my new Employment Pass and that they will issue the Employment Pass on my first day of work with Company A. My first day with company A starts next week. During the probation period (ie the first month with Company A, there can be an immediate termination of notice on both sides)

Now, all these while, I have been continuing interviews with another company (Company B), which is very compelling and has been a bit slow with the interview process. They just verbally offered me a position this week with a similar salary as Company A. Their offer letter etc will take a while to produce. I have not told them anything about Company A as it may damage my potential offer with Company B.

My question is this: I plan to start with Company A (without Company B knowing) and by the time Company B is done with the offer letter, reference checks etc, I will already be with Company A for 2 weeks plus. I may then accept Company B's offer and resign with immediate effect from Company A. The 2 week in Company A will give me a rough idea of whether or not the job / boss is good. Company B will have to apply for an EP for me. Will they be able to know of the existence of Company A? In the Employment Form we are required to list down all previous employments, if i left out company A in the list, will MOM reject it?

Thanks - your advice is much appreciated.