What is your contractual obligation with the current company and the current temp agency? Did you commit to be there until a certain date? Did you receive this new offer knowing that, should you choose to accept it, you would be required to violate the preceding agreement?

As for the new company, if there is a position you qualify for, I so no reason not to try to secure one of those for yourself, assuming a full-time spot is what you are really after.

I would, myself, be cautious trying to overtly leverage any of this. Leverage is by definition, the exertion of force. Some people react very angrily and confrontationally when they sense someone is trying to leverage them. Your HR lady would seem to potentially be a prime candidate. I guess what I am saying is, sometimes leverage gets results, and sometimes, it blows up in your face. I had someone once fail to make good on a commitment to provide me with a bunch of stock in a company I was consulting for. I did all the work, which included finding a company to acquire them. I did that, not her. Everything was roses. Then, their CEO told me to stuff it. I was fairly connected in this industry and I told her she didn't want to hose me. She told me again to stuff it. So, I got on the phone. I told everyone. From Tokyo to Manchester, and everywhere in between. Then, she sued me.

I ultimately won and I got the disputed stock, but because the CEO had done such a poor job, it would up being worthless. The company sold for pennies on the dollar.

I guess all I am saying is, be careful what you wish for. All bets are off when people stop making decisions rationally and instead, base them on emotion. You don't need that. You just want a stable job, or so it sounds.