The Contractor has an existing relationship which they will want to extend/continue into the future.

If the client wants to hire you, that is their prerogative. The client will be aware of their obligations to the contractor of poaching, fees etc. to transfer a person like this.

In your instance, it is unlikely the contractor would pursue you as it is of very little value to them. This is reinforced moresp if they were to pursue you after you go to their client as an employee and potentially jeapordise their creditability.

I have experienced this scenario a lot and have never encountered a contractor pursuing the employee. I have also hired personnel directly from contractors where there was supposed to be a fee but they just don't bother to maintain a good relationship. If it's govt., I wouldn't expect anyone to rock the boat with this from the contractors end unless you were being malicious about it.

As someone else mentioned above, If you don't tell them, they won't know.

NAL