Opposition politicians have demanded a parliamentary probe into the Forth Road Bridge closure.
Scottish Labour’s deputy leader Alex Rowley led calls for an investigation into claims that maintenance at the crucial crossing has been neglected.
He was joined by the Scottish Conservative’s Murdo Fraser, who said the closure was “damaging the economy”.
But Transport Minister Derek Mackay dismissed their concerns, claiming that there are more engineers working on the bridge than ever and that no maintenance was neglected.
Mr Rowley said: “There appear to be a string of issues around the Forth Road Bridge going back years. We need answers as to what has gone wrong here.
“We have seen two senior engineers resign over the bridge and a third claim that key maintenance work was mothballed five years ago.
“This is a serious issue that we need answers from. No stone should be left unturned.
“After eight years in government the SNP need to be held accountable for their decisions and with a majority in parliament there is no excuse for them not to back our call for a parliamentary inquiry.”
Mr Fraser said: “It hardly needs to be stated how damaging the bridge closure is for the economy of Fife and the east of Scotland more generally.
“And while the efforts of the Scottish Government, its agencies and the transport companies are appreciated, there are still problems and the priority must be resolving these.
“But we also need to have a fully independent inquiry into what went wrong, and that has to report early in the New Year.”
But Mr Mackay said there was no need for an inquiry and insisted the Scottish Government was doing everything it can to help alleviate the crisis.
He said that it was “inevitable” that there would be travel difficulties following the closure, but that diversions and additional rolling stock had helped commuters and haulers reach their destinations.
He told the Scottish Parliament that he would continue to monitor the situation and that he hoped the “essential” work would be completed by the New Year.