Investment of half a billion pounds could transform East Anglia’s main rail line – and create tens of thousands of jobs for the region.

That is the verdict of campaigners who are today presenting the business case for the line’s transformation to the Treasury.

They say that every pound invested in the line will bring almost £10 in economic benefit for the region – that is four times the cost/benefit figure for the proposed HS2 line from London to the midlands and north of England.

The business case has been developed by the Great Eastern Rail Campaign, the group comprising local MPs, Local Enterprise Partnerships, business organisations and local authorities.

It is being handed in to the Treasury today by co-chairs Mark Pendlington, chairman of the New Anglia LEP, and Norwich North MP Chloe Smith. They hope to persuade Chancellor George Osborne to include a pledge on the investment in next month’s Autumn Statement.

They are calling for a further £476million investment in the Great Eastern Main Line to allow trains to regularly travel from London to Norwich in 90 minutes. This would give a journey time to Ipswich of 60 minutes and a journey time to Colchester of 40 minutes.

The money would be spent on improving the track over the next five years – including the installation of a new passing loop near Chelmsford to ease congestion problems.

The figure does not include the cost of new trains – and the campaigners want the Chancellor to ensure new trains would be introduced as part of the new franchise for the region, which is due to start in October 2016.

Ipswich MP Ben Gummer is one of the leading MPs behind the campaign and said the investment was vital for the whole region.

He said: “We aren’t doing this because we want to travel in shiny new trains – although that would be very nice in itself.

“We are doing this because it is absolutely vital for the economic success of the region and of Ipswich in particular.”

The business case says that improved rail links would help bring 10,000 new jobs to the Ipswich area, and 14,000 new jobs to Colchester area.

Mr Gummer said: “Those figures are taken from standard calculations which are not disputed.”

The Government has already given current franchise owner Abellio a two-year extension on condition that its fleet of carriages, whose design dates back to the 1970s, are refurbished. That work will start early next year and should be completed by the end of the current franchise.

Colchester MP Sir Bob Russell put his weight behind the campaign – saying it was about time the region got the support it deserved from central government.

He said: “There are many things that can be done to improve things, I know that there should be more capacity when Crossrail starts between London and Shenfield in 2018.

“An improved rail service would be very good to attract new business, but we need improvements to the roads as well.

“Overall, though, I’m delighted that we’re talking about government investment in the region. After the south east we are producing the most wealth for the country – it’s about time we get our share of investment.”

Ipswich Labour candidate David Ellesmere backed the document – and said an incoming Labour government would give its backing to investing in the region’s railway.

He said: “The rail line here badly needs investment. Ipswich needs a rail service that is more reliable than at present and that requires investment.

“If this business case is backed by the current government I don’t think there is any chance of Labour overturning that.”