There has been a massive 15-1 Yes vote for strike action to defend ill-heatlh pension entitlement. This gives a mandate for strike action by RMT members not only on London Underground, but in Metronet, TubeLines, EDF, REW and Cubic. The turnout wasn't great, though (over 11,000 were balloted), probably reflecting the fact that this has been very much a top-down campaign so far.
Here's RMT's press release ...
RMT seeks guarantees on ill-health pensions