A Sunday level of service will operate with some additional services on the rural routes. The following engineering work will affect services: 

Engineering work between London Liverpool Street and London Fields / Stratford:
A shuttle train service will operate between Stratford and Gidea Park, connecting with the bus services detailed above.There are no National Express East Anglia services between London Liverpool Street and Stratford
Customers travelling to/from central London should use London Underground Central Line services between London Liverpool Street and Stratford. 
Train services to/from Audley End (for Cambridge) & Stansted Airport (including Stansted Express services) will start from/terminate at Tottenham Hale, with no One Railway services between Tottenham Hale and London Liverpool Street/Stratford.
Train services to/from Enfield Town, Hertford East and Chingford will start from/terminate at Hackney Downs, with no National Express East Anglia services between Hackney Downs and London Liverpool Street.
Customers travelling to/from central London should use London Underground Victoria Line services between Kings Cross St Pancras and Seven Sisters/Tottenham Hale/Walthamstow Central 

- Engineering work between Gidea Park, Billericay and Ingatestone :
Replacement bus services will be in operation between Gidea Park and Billericay for connections with train services to/from Stratford, and Southminster & Southend Victoria. An additional bus service will also operate betweeen Billericay/Wickford and Laindon for connection to C2C services to/from London Fenchurch Street.
Replacement bus services will also be in operation between Gidea Park/Romford and Ingatestone for connections with train services to/from Stratford, and Colchester, Ipswich & Norwich

- Engineering work between Cambridge and Ely :
Replacement bus services will be in operation between Dullingham and Cambridge, and also between Audley End and Cambridge, calling at all stations.