We present the spectroscopic confirmation of brightest known gravitationally lensed Lyman break galaxy in Epoch Reionisation, A1703-zD1, through detection [C II] at a redshift z = 6.8269 +/- 0.0004. This source was selected behind strong lensing cluster Abell 1703, with an intrinsic L$_{UV}$ ~ L$^*$$_{z=7}$ luminosity and very blue Spitzer/IRAC [3.6]-[4.5] colour, implying high equivalent width...