A WELSH MP who dismissed calls for a third Severn bridge as linking "one thinly populated part of England to another thinly populated part of England" has been challenged to join the queue of early morning motorists heading to Gloucester on the A48.

Newport West Labour MP was concerned that a third bridge – supported by Forest MP Mark Harper – between Chepstow and Over would be paid for by retaining tolls on the current crossings.

In a debate in Westminster called by Newport East MP Jessica Morden, Mr Flynn said: "Is he (Mr Harper) now suggesting that we should have another bridge that goes from one thinly populated part of England to another thinly populated part of England, which then becomes a financial burden on the people in south Wales, because those people will be paying tolls on it to use the main crossing from Wales to England?"

Mr Harper said he had asked the Highways Agency to look at possible options for a third bridge.

"I asked because that detailed option appraisal work has not been done, so I have no idea where there may be sensible routes to cross the river, how much they might cost and what kind of traffic flows might be diverted.

"All I am asking at this stage is for the Highways Agency to respond to my request to consider the options, and for the Minister not to shut off future debate about what the tolling regime should be."

Responding to Mr Flynn, he said: "If he thinks that the area is thinly populated, I suggest that he goes there on a Monday morning at about 7am to sit in a queue of traffic. He will see that it is not as thinly populated as he might think."

Ms Morden, whose constituency includes Caldicot, called for "openness from the Department for Transport and the Treasury" about the plans for the return to public ownership of the bridges due in 2018.

She said: "My constituents need some kind of light at the end of the tunnel.

"But what was so unfair about the Severn Bridges Act 1992 was that it introduced a concession so rigid and inflexible that the toll cannot be varied to help in difficult economic times without the taxpayer incurring liability.

"Any request to modernise the bridges receives the stock response that the government cannot make any changes without extending the concessionary period even further or charging the taxpayer.

"The situation is unfair, because Severn River Crossing plc is fully compensated for any change that comes along, and it can whack the tolls up year after year in line with the 1992 Act. The Treasury is happy because it keeps the VAT and other tax income, and it quietly does well out of the bridges, but bridge users are stung time after time, and they have to pay more for longer.

"I called the debate because I want to articulate the real frustration that bridge users feel, and to ask the Minister explain openly where we are and what the government are planning."

Roads minister Robert Goodwill said tolls will need to continue for one or two years after the bridges return to public ownership to cover an estimated £88 million debt.

With the bridges back in public ownership, VAT will no longer be charged on tolls but Mr Goodwill declined to be drawn on whether charges would be reduced to reflect that.

If the tolls were to remain the same, businesses will no longer be able to claim back the tax so would effectively face a 20 per cent hike in the charge to cross.

Mr Goodwill said: "No decision has been made, and I suspect it would be above my pay grade to make that particular decision. It is probably slightly early to consider that point."