Transpennine Express trains have 25% off advance tickets sale, which has already started and will be on sale till Monday.
Railcards discounts ARE valid in conjunction with this offer. A usual 33% Railcard discount turns into 50% discount. If one is age 16-18 one could combine the current offer with this one (http://www.hotukdeals.com/deals/50-off-tpexpress-advance-train-tickets-age-16-18-jobseekers-hold-a-16-25-railcard-2492146) and get an insane 62% off. Manchester to Newcastle for £6.75! each way. Any questions about this, put a comment and I'll reply.
"Book train tickets this weekend and save an extra 25% in our Black Friday Sale.
This offer is available on over 85,000 train seats for travel from now until February and must be booked by midnight on Monday 28 November.
* Please note that this offer is only valid on tickets that are wholly on TPE services or connect to/from TPE services. Tickets must be for travel between Saturday 26 November 2016 to Saturday 20 February 2017 exclusive of Friday 23 December 2016 to Monday 2 January 2017 (inclusive). Offer is available in conjunction with Railcards.
Don't forget Quidco/TopCashBack and Nectar points.