Work on the new tracks in Princes Street was halted by the row
A row has broken out over the reasons behind delays to the £500m Edinburgh tram project.
Work due to start about three weeks ago to lay tram tracks in Princes Street, was halted amid claims that contractors were demanding an extra £80m.
However, a firm representing the German contractor Bilfinger Berger said the project stalled because of a dispute over thousands of pounds, not millions.
Project manager Tie said the contractor has not put forward any resolutions.
When the work was stopped, Transport Initiative Edinburgh (Tie) accused the contractors, Bilfinger Berger, of imposing new conditions that could add £80m to the cost of the project.
But consultants to Bilfinger Berger, Citigate Dewe Rogerson, said its client had "sought to find a solution to the trams contract problem with Tie".
Its managing director, John Mullin, said: "It is regrettable that agreement has not yet been reached.
"Whilst recognising that the contract allows for mediation on individual disputes, this will not deal with all of the issues already identified and notified to Tie in a timely manner.
"The dispute comes about regarding the provision of temporary bus lanes in Princes Street.
"Bilfinger Berger put in a quote for this but the estimates were disputed by Tie and the difference was thousands of pounds, not millions."
Tie said the dispute centred on the "unacceptable conditions" demanded by contractors before it started laying tracks in Princes Street, Edinburgh's main thoroughfare.
But Mr Mullin claimed there were currently about 100 issues outstanding.
He added: "Therefore, in the interests of moving forward for the sake of all parties involved, and those indirectly affected, we suggested that an independent figure or body convene a round table discussion to seek an encompassing and lasting solution to the current impasse.
"However, we understand that this proposal has not been acceptable to Tie."
Edinburgh City Council released a statement denying the contractor's claim that it suggested the intervention of an independent body.
It said: "Under no circumstances did Bilfinger Berger formally put the request forward to Tie."
A spokesman for Tie said: "Tie has not received any formal request from Bilfinger Berger that suggests any other route to resolving this dispute.
"The contract which has been signed by Tie and the consortium contains a dispute resolution procedure and the purpose of that is to resolve this type of issue."
Princes Street remains closed and if the dispute is not resolved by the end of next week, independent experts will be called in, which is expected to add to delays and costs.
Lothians SNP MSP Shirley-Anne Somerville demanded an urgent resolution to the dispute.
She said: "From day one this project has been dogged by disputes and delays, and frankly both sides need their heads knocked together.
"People in Edinburgh are not interested in a war of words, they want action and an end to the disruption.
"The bottom line is that the disruption being inflicted on Edinburgh residents and businesses must end."