The Pound could break through support and head back down into the channel, targeting the 0.618 from the possible corrective ABCD-like pattern that would form. In general, given the "brexit" hurdle I think it is plausible to assume a push down of the pound heading towards the vote, the outcome of which will certainly have the last word on the sterling's destination (and the euro for that matter).
Alternatively, a strak of weak US economic data and a continued dovish stance from the FED could cause the pound to bounce on that support and continue it's uptrand.
Wow... what a remarkable event. Now the question is, will this just dissipate on a future contraddicting poll news? There's no way to know really