Ordinarily, no. In fact, the liquid level would usually rise in the tube until it is at the same height as in the main tank, so your gas would be very far from the end of the tube. To see why, imagine the surface of the liquid directly above the the end of the tube. The pressure is P1. That pressure gets transmitted through the liquid down to the end of the tube. But there's a second source of pressure there: the weight of the water above the end of the tube. So the pressure there is always greater than the pressure P1. The pressure in the gas, however, is always just about exactly P1. So any gas at the end of the tube would get forced back into the tube. It could never bubble out.
Now, maybe if I were to break enough rules, I could get a few bubbles briefly. But for an ordinary tank, with uniform pressures, ordinary materials, no relevant capillary actions, only gravity involved, etc., the answer is no. You need some sort of pump to raise the pressure in the tube, and make it different from the pressure in the gas directly above the liquid.