Norfolk MPs yesterday presented a letter to Transport Secretary Justine Greening, urging her to invest in improvements to a rail bottleneck which is slowing down East Anglia's economy.

South West Norfolk MP Elizabeth Truss, Mid Norfolk MP George Freeman and West Suffolk MP Matthew Hancock have been pressing for a �25m upgrade of Ely North Junction, at Queen Adelaide, Cambs.

The work would enable half-hourly trains to run between King's Lynn and London, and speed up services between Norwich and Cambridge.

It would also enable more frequent services to run between Ipswich and Peterborough.

After the meeting, Ms Truss said: 'Today's letter to the secretary of state illustrates the total commitment by members of Parliament, councils and businesses to see the upgrade of the Ely North junction.

'The government has consistently highlighted that improvements in infrastructure will generate growth. By upgrading Ely North and removing the current bottleneck at the junction, this will create the opportunity for a Kings Lynn and Norwich Flyer service, with increased frequency.

'Last month the Secretary of State said that she wanted to even out the rail spend across the whole of the country and I believe Ely North is on the right tracks to benefit from this.'

Mr Freeman said: 'The infrastructure needs of our region have for too long been neglected by Governments.

This region has the businesses, science, innovation and enterprise to play a major role in the UKs economic recovery, building the businesses and jobs of tomorrow. But we will never build a 21st Century Economy on 19th Century infrastructure.'

Matthew Hancock MP said: 'Double tracking the Ely North railway junction would bring a big boost to the town of Brandon, and the wider East Anglian economy, at an affordable cost.

'Brandon will benefit from a twice hourly service to Cambridge, which will help address previous levels of under-investment in rail and better connect the town to one of the country's fastest growing cities.'

MPs have been calling for improvements to Ely North junction, where the Lynn - London and Norwich - Cambridge lines meet, to be made a condition of the new Thameslink, Southern and Great Northern rail franchise.

The �25m scheme, which involves dualling a section of track, would enable half hourly trains to run between King's Lynn and London, providing a boost for the West Norfolk economy.

It would mean whoever takes over the franchise to operate trains between King's Lynn and London, after First Capital Connect's tenure ends next year, would have to carry out the work.

In January, Norfolk MPs held a rail summit in Westminster supported by LEPs and local councils to highlight East Anglia's rail network.

In May, Ms Truss met with the Secretary of State for Transport Justine Greening, who promised to 'even out' rail spending across the country.

The upgrade of Ely North will benefit the Kings Lynn, Ely to Norwich and Ely to Peterborough lines. There will also be benefits for the movement of freight transport. Currently the Ely North Junction is creating a bottleneck which is impacting on the economic growth of the area. Fen Line use increased by 2pc more than the national average increase in 2010/11. Downham Market has seen a 64pc increase in usage since 2002/03 – an extra 160,000 passenger journeys. A public consultation, which began two weeks ago, ends on August 23.