offer for consulting position runs out before further interviews

Hi all,

I have been offered a consultant position. However, the offer is contingent on accepting it within two weeks. Problem is I have all other interviews with interesting and preferable consultancies (McK, BCG...) after that two week period, meaning I have two options:

1) accept the offer, thus depriving myself of all the other opportunities

2) reject the offer, risking that I don't receive another offer and end up with nothing

Is there any advice what to do in such a situation?

Thanks guys