Norwich MP Chloe Smith has insisted the pressure is being kept up over the installation of a new swing bridge at Trowse - key to getting train services from Norwich to London in 90 minutes.
Network Rail recently published details of how it will spend more than £2bn to improve the rail network in East Anglia between 2019 and 2024.
But, while the Anglia Route Strategy Plan gave details of how it will enhance existing infrastructure, it did not include provision for major improvements the Great Eastern taskforce had flagged up as crucial to speed up trains.
One of those is the replacement of the single track swing bridge at Trowse with a new fixed double track structure - seen as essential to making it possible to have regular 90 minute services from Norwich to the capital.
The Great Eastern taskforce, chaired by Norwich North Conservative MP Chloe Smith met this week and she said pressure was still being brought to bear over the improvements which are needed.
Ms Smith said: 'The task force is carrying on its work to ensure infrastructure improvements are being done.
'There are five key projects, including the Trowse swing bridge, which we know are required to make all our Norwich to London service run faster and more reliably.
'We know that the swing bridge is on of the important projects and we have assurances from the minister that it is being looked at.
'I will continue to work very hard with the task force to make sure that project is done.'
Greater Anglia recently released photographs of the new carriages which are being manufactured in Hungary and Switzerland.
Greater Anglia is spending £1.4bn on 169 new trains, which will start running next year, with the operator pledging two Norwich in 90 services each week day.
Ms Smith said: 'It is good news that we will have selected services in the near future which are running within 90 minutes, but the real goal is for all services to do that.
'It is a huge achievement to have got new train carriages on their way and that is down to the work by the task force to date.
'That is so important to existing passengers in Norfolk, but will also bring more passengers and new jobs in the future.'
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here