Labour's gains are around 60% of that number. The smaller size of a ward compared to a parliamentary constituency means that you always get a wider selection of parties in the running, so it's not especially surprising that other parties have picked up seats, and the reduced importance makes tactical voting less of a priority.Interesting to note that the Tory council seat loss is broadly as bad as expected, but Labour’s gains are only around 40% of that number. That means it’s not a simple switch between the two, with Lib Dem’s, Greens, Galloway/workers and independents taking seats that Labour should/could have won. Even Sky are now saying that, based on yesterdays vote share, Labour would struggle to get a majority at a general election. Interesting times.
It's difficult to compare the vote share in local elections to generals. You can only really look at swings, since there weren't any council elections in a whole swathe of urban areas where Labour have a much larger vote share. Given that Sky tend to employ fairly low rate commentators to waffle non-stop, it's most likely that they've just taken the raw vote-share figures and not stopped to think about it at all.