It should do- maybe they wait until nearer the time and increase it based on the RPI/CPI at the time. It 'll probably go up to around £6.40, but maybe they'll cap the increase at 1% like benefits
Yes its usually mentioned in the March budget but I can't find it this year.
It would be very unusual for it to change outside of a budget announcement but I suppose there's always a first! I just wanted to check I wasn't missing anything so far.