The Cable is traded within a box of about 350 pips and as long as this box holds, heavy selling is not recommended. If, however, the lower band of the box is broken to the downside, which seems likely, risk of shorting the Cable will be negligible and we will expect the Sterling to go down to the 1.5538 level.
In the last week, the long positions were reduced and short positions increased which implies that the market is disappointed of the continuation of Cable rally which will make our bearish scenario more likely.
All in all, in the short term we favor fluctuating within the box and provided we have a downside breakdown of the box, we will turn completely bearish on Sterling for the intermediate term.
Disclosure: I have no positions in any stocks mentioned, but may initiate a short position in FXB over the next 72 hours.