Those who have signed up as affiliated supporters via unions such as Unite in the past six months will not have a vote in the leadership contest, and must purchase "registered supporter" status.
Labour's NEC procedures committee has ruled that a back-dated "freeze" on memberships also applies to affiliated organisations.
In the days since the NEC announced the re-introduction of the six-month rule - meaning that those who joined the party after January 2016 will not get an automatic vote in the Labour leadership election - many people have sought to join organisations such as Unite to gain a vote without paying Labour's £25 "registered supporter" fee.
Yet, as we warned yesterday, the regulations on voter eligiblity were not due to be released until today.
Now The Times' Lucy Fisher has posted information suggesting the union route will not be possible.
NEW: Labour NEC procedures cmte has ruled 6-month freeze date applies to affiliates in leadership contest. Stops £2 sign ups by Unite et al
— Lucy Fisher (@LOS_Fisher) July 14, 2016
If you want a vote in the leadership and haven't been a member of the Labour party or an eligible affiliate organisation, then it may well be time to rustle up twenty-five quid. Registration opens Monday.