The first test trains are due to run over the new Ipswich Chord from Monday.

The chord – which links the Felixstowe branch with the north-facing main cross-country line to Peterborough, the north and midlands – will be fully opened for cross-country trains from March 31.

Its opening will cut journey times by between 45 and 75 minutes as trains no longer have to reverse in the Ipswich freight yard.

Work on the £35 million project started in 2012, and received a major grant from the European Union to help finance the scheme.

Rail minister Stephen Hammond visited the site to see the progress of the work. He said: “This is very important for Felixstowe, this region and the country as a whole. It will make it much easier to get goods to and from the port.

“It also has a very important environmental benefit because it should take many more lorries off the roads.”

Some freight trains will continue to use the main line south towards London, but the growth in rail traffic from the port will all be taken up on the cross-country main line which has been upgraded to take larger containers.

As well as the Ipswich chord, there have been other improvements to bridges and extra track near Ely. There could be further investment in the route in future years.

Ipswich MP Ben Gummer said: “This small section of track will make a big difference to Ipswich and Suffolk commuters.

“The new direct link to Felixstowe means that as many as 24 freight trains can pass smoothly and efficiently to and from the port.

“The benefits do not stop there. The new Ipswich chord will take 750,000 lorries of the roads by 2030. This will dramatically reduce congestion for drivers on the A14 – something that has been estimated to cost our economy as much as £80 million each year.”

East of England Labour MEP Richard Howitt has also welcomed the new chord – although he was disappointed that his party’s contribution had not been recognised.

He said: “Although I am disappointed that Network Rail chose not to invite me today as one of the key MEPs who lobbied successfully to get the rail improvements being celebrated today, I remain satisfied that businesses and commuters will enjoy better rail journeys in the future thanks partially to Labour action in the European Parliament.

“The Government was happy to accept the European money and it is ungracious for them to seek short term political credit for a lot of investment in which we all played a part.”