"Mistakes" made in the 1987 contract governing the operation of the West-Link bridge were repeated in the 2001 contract for the second bridge, Fine Gael transport spokeswoman Olivia Mitchell has claimed.
Ms Mitchell now wants the 1987 contract, which was signed on behalf of the State by disgraced former Dublin assistant city and county manager George Redmond and former minister for the environment Pádraig Flynn, to be tested in court.
She said a key clause, described last week as near valueless by National Roads Authority chief executive Fred Barry, could have been used to force National Toll Roads (NTR) to ease congestion at West-Link bridge.
Mr Barry said the authority's legal advice was that while the clause appeared to offer certainty, in fact there was no measure of penalty in the contract for transgression of the clause.
Breach of the clause in itself did not invalidate the contract.
The clause, section 6 (b) of the 1987 contract, stated: "The toll company shall provide facilities for the collection of tolls which are adequate having regard to the volume of traffic using the road."
However, Ms Mitchell has accused the NRA of having "made no effort whatsoever" to enforce the clause and of allowing it to be "lifted" without any amendment into the 2001 supplementary contract covering the building of the West-Link bridge.
"The very fact that the second bridge was needed was proof that congestion was a problem in 2001," she said.
"If you had a contract like that in your drawer, wouldn't you have been all over it seeking a way, a measure, to improve traffic flow?"
The relevant wording in clause 5 (8) of the supplemental agreement in 2001, said: "West-Link shall provide facilities for the collection of tolls which are adequate having regard to the volume of traffic using the toll road."
Ms Mitchell is now demanding that Minster for Transport Martin Cullen should sue National Toll Roads for the alleged breach of the 1987 contract.
National Toll Roads has consistently maintained that the two-lane motorway and the junction design rather than the West-Link plaza is the cause of most of the traffic congestion on the M50.
The upgrade programme will increase the traffic throughput through the expansion of the motorway to three lanes in each direction.
