The link between minimum wage and inflation isn't quite so basic as ymb makes out. It does depend a lot on the level: clearly, setting a minimum wage of £50/hour or some such nonsense would be pretty destructive, but the more modest adjustments under consideration are nowhere near that sort of stupidity. Meanwhile, a quick glance at the inflation rate in the UK over the last 20 years (ie, since the Minimum wage was first introduced) shows that inflation has not been overly affected in the same period. The reason for this is that hiking the minimum wage doesn't actually introduce that much more money into the system.
That last statement (ie no direct causal link between minimum wage and inflation) does depend a little on which inflation index you use; the CPI is generally held to be more robust, and that doesn't track the Minimum Wage at all, instead being more correlated with wage increases generally (and then still lagging behind). The RPI tracking is a little less clear, but it still appears to have tracked overall wage growth more closely than minimum wage growth.
Nor does "taking the incentive away" seem to follow. Introducing a minimum wage doesn't set all salaries to be the same, only the entry-levels. And what incentive can you provide that encourages people to get older, which they were going to do anyway?
ymb's economic analysis therefore seems to be far too simplistic. As I say, I'm happy to accept that this argument can only be carried so far, but as long as the minimum wage is increased sustainably it's simply not true to say that it will be counterproductive. As not that many young people are in work anyway (thus reducing the overall impact), then this should remain the case.