The following East Coast trains will be cancelled from Monday 13th August:
Mondays – Fridays (and Saturdays for Leeds)
05.26 Stirling – London King's Cross (service will start at Edinburgh) - from 27 August
09.03 London King's Cross - Leeds
11.45 Leeds - London King's Cross
15.00 London King's Cross - Stirling (service will terminate at Edinburgh) - from 27 August
15.03 London King's Cross - Leeds
17.45 Leeds - London King's Cross
Sundays
13.33 London King's Cross - Leeds
17.16 Leeds – London King's Cross
16.04 Newcastle – London King's Cross (amended service - additional waiting time at Doncaster)
https://www.lner.co.uk/travel-information/leeds-timetable-changes/
The LNER advice is that if you have a booked advance ticket on any of the listed trains to "please travel on an earlier or later LNER train on the same day".