Lowestoft must prove that a third crossing will bring in twice what it costs in terms of economic benefit to the town to be sure it is a top priority for government funding.

At a consultation event for businesses held at Lowestoft's Orbis Energy Centre, Waveney MP Peter Aldous said there was a 'real desire to build this crossing, both nationally and locally' after prime minister David Cameron promised it would be built by 2020 during this year's general election campaign.

'However, government won't give us a blank cheque,' said Mr Aldous, who is chairing a steering group looking at the delivery of the third crossing.

'There are procedures we need to go through to show the scheme works.'

As part of that, Department for Transport guidelines state that the crossing would need to have a benefit:cost ratio of two - which means that the scheme would effectively pay for itself twice over in terms of the economic benefits it brings to the area.

'What government are looking for is that if they spend £100million, is it going to produce a dividend of £200million?' Mr Aldous said.

He admitted that 'sounds like quite a big obstacle' but said: 'We can do it.

'However, we need as much feedback as possible. I need as much ammunition as possible to take to the prime minister.'

Part of the purpose of yesterday's consultation, organised by the Lowestoft and Waveney Chamber of Commerce, was to gather businesses' views on how the lack of a third crossing has held them back in the past - and how it can help them to move forward in the future.

Consultancy firm Mouchel – which has been tasked with developing a business case for the third crossing – spent the event collecting examples where businesses had not moved to or invested in Lowestoft because of its traffic woes, as well as cases of firms which might want to come to the town if things improve.

Mr Aldous also said statistical data on work hours lost in traffic or cost revenue would also be valuable to building the business case and he encouraged as many businesses as possible to get in touch with him with their views to help prove the economic case.

'We need to get as much information to give the experts what they need to be able to prove and demonstrate that it is going to bring those benefits,' he said.

'Going up to Westminster, I can't have enough feedback,' he said. 'I'm like a head of an army taking to the case to government.

What impact do you think a third crossing would have on Lowestoft? Write, giving your full contact details, to: Journal Postbox, 147 London Road North, Lowestoft NR32 1NB or email andrew.papworth@archant.co.uk