The line includes stops at Grantham, Sleaford and Boston train stations.
Trains will depart from Nottingham at 9.41am, 11.57am and 4.29pm and return from Skegness at 12.27pm, 2.10pm and 7.15pm.The service reductions are due to a short-term issue with staff availability.
In addition, East Midland Train services will not run on these routes:
Nottingham to Liverpool – customers are advised to use alternative train operators’ services.
From Nottingham, Lincoln, Newark North Gate and Cleethorpes - due to pre-planned engineering work, rail replacement bus services will be operating.
A rail replacement bus service will run between Derby and Nottingham, calling at Beeston, Long Eaton and Attenborough.
The timetable to/from London will not be affected and a normal service will operate throughout the day on this route. Due to pre-planned engineering work by Network Rail, rail replacement buses will replace trains between Corby and Kettering.
A spokesperson for East Midlands Trains said: “We are very sorry that customers may experience some inconvenience when travelling with us this Sunday.
“All of our London services will continue to run as normal throughout the day and we will continue to operate a number of train services on our busiest routes. We have arranged replacement bus services to make sure that customers can still get to their destinations and we are arranging travel on alternative train operators wherever possible.
“We’d advise anybody planning to travel on Sunday to check our website, eastmidlandstrains.co.uk or follow us on twitter @EMTrains for the latest advice and service information.”
Customers with a pre-booked East Midlands Trains ticket who decide not to travel on Sunday will be able to claim a full refund.
Alternatively, customers can use their East Midlands Trains to travel on either Saturday, August 1 or Monday, August 3.
Other train operators will be accepting East Midlands Trains’ tickets and a full list of alternative rail routes will be available at eastmidlandstrains.co.uk from tomorrow (Friday).