When prime minister David Cameron visited Lowestoft during the 2015 general election campaign, he could not have been clearer.

'It has got to be done in the next parliament,' he said. 'It has gone on long enough.

'The electorate know what they're getting with the Conservatives. They get the A11, they get the A12, they will get a third crossing.'

And just in case there was any doubt, transport secretary Patrick McLoughlin and chancellor George Osborne both reiterated the pledge.

However that has led people such as businessman Peter Colby – who is proposing his own barrage idea – to ask why a business plan is needed if the most powerful person in the country has said it will happen.

But Waveney MP Peter Aldous has said: 'You can't realistically, at a time when there's not a great deal of money around, be expected to be given a blank cheque – that's not going to happen.'

He said any scheme across the country would have to prove that the money being spent is value for money.

He has also stressed that no government has made such a clear commitment on building a crossing.

'We have a once in a lifetime opportunity to get together and make this happened,' he said at yesterday's consultation.