If you do not disclose now and should you be caught later then its is going to be 75%tax + 10% penalty.
If you disclose now it is 50% tax. You can at least enjoy the remaining 50% after the lock in period of 4 years. The government is using this carrot to lure out the last one hiding in the borrows. This way the govt will end up having more money in its coffers.
Btw, How much are you planning to resist?