BBC:

Home Office minister Robert Goodwill said security was being "stepped up" as migrants continue to try to board vehicles heading to Britain.

But a lorry drivers' group called the wall a "poor use" of public money.

Work is expected to start this month, with the wall due to be finished by the end of the year.

The BBC understands it will not replace any existing fences.

The government refused to confirm the cost of the wall, but reports suggest a£1.9m price tag - to be paid for out of £17m announced by David Cameron earlier this year.

Speaking to the Home Affairs Committee of MPs on Tuesday, Mr Goodwill said: "The security that we are putting in at the port is being stepped up with better equipment.

"We are going to start building this big new wall very soon. We've done the fence; now we are doing a wall."

But Richard Burnett, chief executive of the Road Haulage Association, called the plan a "poor use of taxpayers' money".

He said funding for a wall "would be much better spent on increasing security along the approach roads".

Vikki Woodfine, of law firm DWF, works with many hauliers and said a wall "isn't the answer".

"It is simply a knee-jerk reaction that is unlikely to make a difference in the long run - particularly since the route to the Calais port is already surrounded by fences and barbed wire," she said.

She said the "real problem" was a lack of policing.

"Chaos reigns in the Calais region, yet hauliers are being fined up to £4,000 per migrant found in their vehicle," she added.

Many of the migrants living at the Jungle and other camps in northern France attempt to reach the UK by boarding lorries as they approach ports or the Eurotunnel.

Numerous fences have been built to protect the port, and the Eurotunnel terminal and train tracks on the other side of Calais.

On Monday, French lorry drivers and farmers blockaded the main motorway route into Calais in a protest calling for the closure of the Jungle.