GMB Ballot Paper for Leader of the Labour Party

I'm not a member of the Labour Party but then again I'm not "a supporter of any organisation opposed to it" so according to my GMB ballot paper I can vote for the next leader of the Labour Party.

There is encouragement on the form to vote online as it is

immediate

secret and secure

carbon neutral

saves GMB money

Fine.

To vote online you have to enter the Security Code part one and the Security Code part two from your ballot paper. Guess what? My ballot paper has a blank security code part one and a blank security code part two.

I can't be the only one, can I?

So my vote is going via Royal Mail.