I'm posting it here under the rule that it is rejected comments that are most interesting (the site, a standard WordPress design, is purportedly open to comments, but only one suspiciously unctuous comment has actually made it to below the line. Ho hum!).
Classifying Corbyn's statement that he would commemorate all those who have died in the cause of Irish independence as "support for the IRA": just a tad crude? Would there have been a Good Friday agreement without the left's recognition of the justice of the republican movement?
Of course, that doesn't stop anyone misrepresenting Corbyn's views in the way that you suggest. But it would still be a misrepresentation. The English electorate may well be ignorant enough to find such over-simplification attractive; but that is hardly a recommendation. Fortunately the electorate has other sources of information than admen's billboards these days.
Neither would participating in a "minute of silence" (however convened) be equated with endorsement in most reasonable people's minds: politicians should pause for reflection more often!
Update 28/11/16: Nice example of how anyone can get caught up in a minute of silence.