The FTA has demanded assurances from Scotland’s transport minister that the Forth Road Bridge will re-open to all vehicles on 4 January.

The closure of the bridge has caused huge financial headaches for many logistics companies, with vehicles forced to take a 50-mile detour via the Kincardine Bridge, which has experienced 11-mile tailbacks at the busiest times.

The trade association said it knows of one parcel firm that is reporting additional costs of £11,000 a week for fuel and extra drivers as a result of the closure.

FTA’s policy director Karen Dee has written to Derek Mackay, minister for transport, requesting confirmation that the bridge will reopen on 4 January as announced.

Dee said: “FTA very much welcomes the efforts of Transport Scotland in helping to secure relaxations to the Drivers’ Hours rules to ease the pressure, and also with the addition of vans carrying freight to the permitted users of the HGV and bus priority lane on the diversionary routing.

“But what the logistics industry really needs is the bridge open to all traffic – including HGVs – as soon as possible so that the additional costs and uncertainly the industry is currently experiencing can be brought to an end.”

Mackay said: “To date our absolute focus has rightly been on getting the bridge reopened as quickly and safely as possible, and ensuring a credible travel plan is in place to minimise disruption.

"I don’t think anyone would question that approach, and it’s important the engineers and experts have had space to fully concentrate on the complex repairs.”

The bridge has been closed since 4 December after a fault in the steelworks was discovered during a routine inspection.