Apparently it is on Sky Sports Plus (as the English, Scottish, Welsh / Northern Irish games are on SS 1, 2 and 3 respectively).
Irish bars should have the Irish (Rep) game on ... depending on where you are the best bet may be a pub on Westminster Bridge Road near the junction with Waterloo Road (St George's Circus). It has the word 'Flowers' in its name I think but I can't remember its full name. In the past they have shown both Republic and English games when they have clashed at the same time (different games on different screens).
I'm afraid I don't know any Irish bars that I can be sure will show the game at the other end of SE1 if that's where you will be.
Apologies to anyone who might have followed my (bad) advice. When I got there just in time for kick-off myself I was surprised to see that every screen was showing the England game and none were showing the Swiss-Irish match. I didn't hang around long enough to ask (off searching, in vain, for a pub that was showing the game) but I presume this means they are under new management?
When I first moved to the area there were two pubs around the corner where I could watch GAA and Irish international matches - the other one is a Chinese take-away now.
I suppose the fact that people weren't going regularly enough to realise they were closing down was part of the reason they closed down.