Train bosses have been called to deliver an action plan to resolve 'unacceptably poor' service along two major rail routes.

Norfolk MPs Brandon Lewis and Chloe Smith have written to Greater Anglia's managing director Jamie Burle about ongoing problems on the Great Yarmouth to Norwich line and Norwich to London Liverpool Street.

The MPs said problems have been "ongoing for a significant period of time".

In the letter, the MPs wrote: "In principle the Great Yarmouth to Norwich line should be a popular service. Many of our constituent's commute between Norwich and Great Yarmouth daily, and our strong tourism industry attracts literally millions of visitors to Great Yarmouth and Norwich over the calendar year.

"As you know this opportunity has been undermined by the ongoing service delays, disruptions and cancellations.

"These problems are exacerbated by the on-going problems on the Norwich to London Line, which has also experienced significant disruption, causing unacceptable disruption to our constituents, many of who have complained of missing meetings and disruption to their work."

Delays on the mainline in recent weeks were caused by points failure at Liverpool Street and various problems with freight trains said Greater Anglia.

The MPs wrote the recent difficulties were not all in the company's control and there were opportunities with the introduction of the new fleet of trains.

But Greater Anglia said it was implementing a number of actions including additional works in partnership with Stadler to overcome 'teething' problems with the new trains, speed up completion of testing, action for smooth operations at the Norwich Crown Point depot

The company said it was reviewing and revising contingency plans for when problems occurred.

A Greater Anglia spokesperson said: "We believe these initiatives will result in a progressively improving service in the weeks ahead, so we can then consistently provide the high quality service customers rightly expect and we intend to deliver. We are passionate about providing the best possible train service for customers and communities across the county and we are confident that the new trains will ultimately transform our railway - with better performance, many more seats, an enhanced travelling environment and much improved accessibility."