A high precision measurement of the proton elastic form factor ratio μ_pG_Ep/G_Mp in the range Q² = 0.3 - 0.7 GeV²/c² was performed using recoil polarimetry in Jefferson Lab Hall A. In this region, previous data from LEDEX (G. Ron et al., Phys. Rev. Lett. 99, 202002, 2007) along with many fits and calculations indicate substantial deviations of the ratio from unity. In this new measurement, with 80% polarized electron beam for 24 days, the proposed statistical uncertainties were achieved (<1\%). Preliminary results are a few percent lower than expected from previous world data and fits, indicating a smaller G_Ep at this region. Beyond the intrinsic interest in nucleon structure, the improved form factor measurements also have implications for DVCS, determinations of the proton Zemach radius and the strangeness form factors through parity violation experiments.