Rail travellers and businesses across East Anglia are still waiting to hear whether a long-awaited investment programme to improve the Great Eastern Main Line is still on track.

But there are high hopes that a £476 million upgrade to the line from Liverpool Street to Norwich through Ipswich and Colchester will get the go-ahead as part of Chancellor George Osborne’s Autumn Statement process.

It is top of the list of “must-do” items for business groups across the region – a report into the proposal published in the summer said that such an infrastructure boost could bring £4.5 billion of investment to the region.

And the proposal has also won cross-party backing.

Last week shadow chancellor Ed Balls said that any pledge from the Chancellor would be honoured by an incoming Labour government if that is the result of next year’s general election.

Mark Pendlington, chairman of New Anglia LEP said: “This is going to be a hugely important week for the future of our region’s infrastructure.

“We have asked George Osborne for £476 million investment in the Great Eastern Main Line, which will deliver £4.5bn economic benefits for Suffolk, Essex and Norfolk and thousands of jobs – 10,000 in Ipswich alone.

“We have thousands of rail passengers and businesses backing our campaign and have been told by ministers that we have a strong and compelling case. So our hopes are high, as we wait for those words turning into action.

David Burch, head of policy for the Essex Chambers of Commerce, agreed that the upgrade to the rail line was urgently needed.

He said: “Both businesses and rail passengers need to see a major improvement in services and the rail investment is a top priority.”

The announcement on rail investment is expected to come later this week as details of the Autumn Statement – which is due to be unveiled by Mr Osborne on Wednesday – are fleshed out.

If it is announced, it will also be seen as a major success for the region’s MPs. The campaign to get major rail improvements was headed by Ipswich MP Ben Gummer and Norwich North MP Chloe Smith and has dominated much of the time since the 2010 general election.