Perhaps the pound will achieve parity with the euro; perhaps it might even approach parity with the dollar. But so what? The habit of financial writers to call such milestones "psychologically important" just shows that they are in fact economically irrelevant. And the idea that parity with the euro somehow strengthens the case for British membership is asinine: please name one country that has joined it because its old currency was at or close to parity. It is utterly irrelevant.
One worth remembering in the times to come. The arguments in favour and against membership of the euro are nothing at all to do with what rate the exchange rate is. And, as above, from the ex-editor of The Economist, the idea that parity means we should join the euro is simply asinine. Irrelevant even.