In the period 1997-99, Thameslink arranged for all of its 319/1 units to be converted at Eastleigh Works for use on the shorter-distance Luton to Sutton/Wimbledon services, then known as 'Thameslink CityMetro'.
These units lost their first-class seating and were renumbered into the 319/3 series.
They were painted in a navy-blue and yellow livery at this time.

Various refurbishments have taken place since 1999, including:
Minor refresh by Thameslink including new seat covers between 2003 and 2005
Relivery and interior refresh by Railcare Wolverton for First Capital Connect completed in 2010
New passenger information system, new seat covers and an internal and external repaint for units transferring to Northern Rail and similar work for those remaining on Thameslink in the interim, starting in 2014.
In the period 1997-99, Thameslink arranged for all of its 319/1 units to be converted at Eastleigh Works for use on the shorter-distance Luton to Sutton/Wimbledon services, then known as 'Thameslink CityMetro'. These units lost their first-class seating and were renumbered into the 319/3 series. They were painted in a navy-blue and yellow livery at this time.
Various refurbishments have taken place since 1999, including:
Minor refresh by Thameslink including new seat covers between 2003 and 2005
Relivery and interior refresh by Railcare Wolverton for First Capital Connect completed in 2010
New passenger information system, new seat covers and an internal and external repaint for units transferring to Northern Rail and similar work for those remaining on Thameslink in the interim, starting in 2014.
British Rail Class 319