Rail passengers travelling between Norwich and London over the weekends will face disruption for the next couple of months.
Because of track replacement work, people will have to change trains at Colchester.
Greater Anglia has amended its timetable to accommodate the £7 million project by Network Rail.
The work starts this weekend and is due to continue until July.
There is disruption on Greater Anglia rail services between Ely and Norwich due to over-running engineering works at Wymondham.
It is also affecting trains between Norwich and Cambridge which may be cancelled or delayed.
The Department for Transport has announced that Abellio will continue to run the Greater Anglia rail franchise until the summer of 2016.
As part of the agreement the number of off-peak trains between Cambridge and Stansted will double.
Some carriages will also get new seat covers, new carpets, better lighting and power sockets.
Transport Secretary Patrick McLoughlin said:
"This deal means real improvements for passengers on the Greater Anglia network.
"It means more services and better-equipped trains, including international connections via Stansted Airport to the rest of Europe that the region needs."
How did your rail company score in the customer satisfaction survey? Check out the results below.
Which? survey: overall satisfaction scores by company.
- 1. Merseyrail (70%)
- 2. Chiltern (69%)
- 3. c2c (67%)
- 4. Virgin Trains (64%)
- 5. East Coast (59%)
- 6. London Overground (58%)
- 7. ScotRail (56%)
- 8. CrossCountry (52%)
- 9. East Midlands Trains (50%)
- 10. First TranspPennine Experss (48%)
- 10. Arriva Trains Wales (48%)
- 11. London Midland (47%)
- 12. Southern (46%)
- 13. Northern (46%)
- 14. First Great Western (45%)
- 15. South West Trains (45%)
- 16. First Capital Connect (41%)
- 17. Greater Anglia (40%)
- 18. Southeastern (40%)
Rail company Abellio Greater Anglia has said it's "disappointed" by the findings of a new Which? customer satisfaction survey.
The company said they had scored much higher results in the separate National Passenger Survey.
A spokesman added: "We are working closely with Network Rail to provide more consistent and better levels of train service performance building on the improved punctuality we have delivered since taking over the franchise in 2012."
We are also focused on improving train cleanliness and working with our industry partners in making the case for rolling stock upgrades.
Rail passengers are 'not satisfied' with Great Anglia or First Capital Connect, a new survey by Which? has found.Read the full story ›
Station staff working for the rail operator Greater Anglia have voted to go on strike in a row over flexible working.
Members of the Rail Maritime and Transport Union on the West Anglia route backed a campaign of industrial action.
The union has about 100 members involved in the dispute. Its General Secretary Bob Crow has accused Greater Anglia of ignoring agreed procedures.
There is disruption on Greater Anglia trains between Liverpool Street and Southend Victoria due to overhead line problems between Shenfield and Billericay. Trains may be delayed by up to an hour, and some will be cancelled.
There are delays of up to 40 minutes on the Greater Anglia rail between Ipswich and Norwich due to broken down train at Diss. It's mainly affecting trains towards Norwich.
Rail staff on part of the Greater Anglia network are being balloted on strike action after the RMT union accused the operator of "ripping up" procedures.
Members of the Rail Maritime and Transport union on Greater Anglia's West Anglia route will vote in the next few weeks on whether to launch a campaign of industrial action.
The union claims that changes being planned by the company will lead to the axing of station cleaners' jobs.