LNWR timetable significantly slower than London Midland

[RyanOPlasty]

I regularly took Londonmidland Trains from Nuneaton to Euston a few years ago. Times were a little slower than Virgin Trains, but not much.
Typically times were between 1hr 10 and 1hr 20. For example, the 07:27 stopping at Rugby and MK was timetabled to Euston at 08:41, usually arriving a few minutes early
I'll be travelling on the LNWR 07:26 tomorrow, timetabled arrival in Euston is 09:02 a full 22 minutes or nearly 30% longer.

Avanti services still seem to be timetabled to take the same time as Virgin. What's going on?

 

[Bletchleyite]

It appears there is a partial two-track timetable in place tomorrow, presumably due to some sort of engineering work, so this train is slowed due to following the preceding stopper from MKC on the fast lines as far as Harrow.

Picking another Saturday, randomly chose 19th November, it's an 0840 arrival which is the same journey time as you describe as having gone before.

 

[matt]

Yes there is a lot of pathing allowance in tomorrow's schedule but the following Saturday is the 0840 so the usual hour or so from Rugby