Sometimes I wonder why people find pensions so confusing. Then I read the information available and think 'oh yes, that's why.
SilsoeSid is talking about the State Pension Age when he refers to 66. That's the age at which you qualify for your State Pension.
In the LGPS, the Normal Retirement Age is currently 65. (If you've been in long enough, it's lower.) It's called a 'Normal' retirement age because ordinarily they can't force people to go (which is not the case here). Next year when the rules change, it is expected to change to the same as 'whatever the State Pension Age is'.
I believe that there is a Statutory Discretion to be able to waive actuarial reduction on early retirement. That means it's up to each Pension Fund (eg Suffolk, Birmingham, Strathclyde) to decide their policy on it. Therefore, as a contributor to the fund, you are entitled to know what your Fund's policy is. Bear in mind the policy could say 'under no circumstances'; on the other hand it might say 'on compassionate grounds' or 'on appeal to a subcommittee'.
You don't need 100% membership of BALPA in the office / Region / UK in order to benefit from being a member, you just need to be a member yourself and get them to take it on. Though I must say, the one I was in wouldn't help if you already had the problem and then joined (rather like waiting until your house catches fire and then ringing round for insurance quotes).