Nice thought, considering that during my time in, I doubt whether my old man actually ever used my proxy vote, but, itll never happen.
There is no way HMG is ever, ever going to set a precedence for a select, but numerically large, group of the population to opt out of voting purely for financial gain.
One question that they will throw is where do you draw the line? E.g., what about the TA, do you give them voting rights during normal times, tax free status but no voting rights during call up?
Then, how about reservists? Surely they, as persons who can be called upon to rejoin the colours, should also get a cut?
You will also get the argument that this would create a 2 tier military. I assume that you would want to make this voluntary (after all, you could not insist that people are forced to lose voting rights just because they join up), so, you end up with 2 levels of squaddy. Those with no voting rights but loads of cash, those with voting rights and no cash. Situation: Nightmare.
How long would you allow people to opt out for? Maybe for the four years that the last party they voted for are in power? Relinquish tax free status to be able to vote again when they dont like the current powers that be?
Or maybe you could say Nope, elect for tax free status and thats it. Welcome to the European Court of Human Rights when every Tom, Dick and Harry that realises that they could sue when they dont like it anymore (contracts signed and sealed relinquishing a basic free world human right would be worthless) jumps on the bandwagon.
HMG will not touch this with a seven million mile barge pole, regardless of anything that the mil could constructively put forward, at the end of the day, it would be seen as a 200 year step backwards. The rhetoric would be simplified to end up as the following
The rich (those with secondary incomes who dont care about tax free status) get to vote; the poor get paid off and then have no say.
The fact that we are talking about a very small percentage of the population that this would apply to would be completely and utterly irrelevant in the eyes of HMG.
I much prefer the argument that serving HM forces should be given tax free status, with TA, reservists etc being given it during deployments. However, theres more chance of me becoming PM than this ever happening.
If this ever got through, I, personally, will pay the entire British Armys tax bill until I die