Lowestoft faces a race against time to put forward its preferred option for a long-awaited third crossing after the government asked for a 'business case' for a scheme by next March's Budget.

During this year's general election, prime minister David Cameron promised the town would get a new bridge – thought to cost about £80million – by 2020 if a Conservative government was elected.

Waveney MP Peter Aldous also said Mr Cameron, chancellor George Osborne and transport secretary Patrick McLoughlin have all given him personal assurances since May's vote that they support a new crossing.

But while the government had made clear its backing, officials from the Department for Transport (DfT) have also said it is up to the town to provide evidence the project can be realistically delivered and offers good value for money.

The DfT would then determine the merits of the business case, with a view to Mr Osborne making a further announcement about the scheme's progress in the 2016 Budget.

That means a public consultation, consideration of a broad range of options and a detailed assessment of the engineering feasibility and timescales, as well as an environmental assessment, traffic modelling and analysis of the wider economic benefits has all got to be completed in less than nine months.

It would all be carried out using £2million of funding given to New Anglia Local Enterprise Partnership (LEP) from this year's Budget for a detailed feasibility study.

Mr Aldous said the government had 'picked up on the need for Lowestoft' and set an 'ambitious target' – but added: 'That's no bad thing.

'There's a lot to be said for setting ambitious targets. If you are gradually meandering along, things can change and you find the target gets moved.

'The fact is we've been given the opportunity to do this with the money that's been provided for the feasibility study.

'We now need to crack on with this as quickly as possible.'

That view was supported by businessman Peter Colby, who has put forward his idea for a Dutch-style barrage system instead of a high-level bridge.

'I believe we need to be moving quickly,' he said. 'It gives us more impetus.'

Suffolk County Council leader Colin Noble said deadlines are tight but that there is determination to get the crossing built.

'There is absolutely no time to waste,' he said.

'With the clear support of the government for an appropriate scheme, we must now deliver a rock solid case to get the job done.

'This is a once-in-a-lifetime opportunity and we must grasp the nettle.'

Waveney District Council leader Colin Law said it was important to capture everyone's views as well as 'delivering thorough technical assessments of various options on traffic and the local economy'.

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