RBS bosses “undermined” Carillion’s efforts to avoid collapsing, according to a witness statement filed at the High Court in London.

The huge construction firm went into liquidation earlier this week after collapsing under a mountain of debt.

Keith Cochrane, its interim chief executive, accused RBS of taking "unilateral action which in the company's view undermined the group's efforts to conserve cash".

According to a witness statement obtained by Sky News, he said the majority taxpayer-owned bank restricted funding three days before Carillion went under.

But RBS said it had "provided considerable support and forbearance to Carillion over many months", arguing the "restructuring plan put forward by the company was not viable".

It comes as the UK Government said Carillion’s former directors would be investigated amid criticism over pay awards and bonuses.

Meanwhile, Scottish Economy Secretary Keith Brown said there was no reason major projects, such as the £745 million Aberdeen bypass, would be delayed by the construction giant’s collapse.

He said: "There is nothing in the nature of the change which has happened that necessitates a delay but of course we'll keep our eye on the further developments as they take place."

Carillion formed one third of the Aberdeen Roads Ltd (ARL) consortium leading the Aberdeen bypass work alongside Balfour Beatty and Galliford Try.

Mr Brown said the Scottish Government did not expect any cost overruns as a result of the liquidation of Carillion, pointing out that the two remaining partners had made reference to "a hole in the project now between £40 and £80 million".

He said: "That's for them to consider with the banks and lenders that are part of this consortium, that's not for the Scottish Government to fill that hole."

Mr Brown said there were around 70 direct employees of Carillion working on the contract as well as about 190 employed on other terms, including some agency staff.

"I think it's likely that the two remaining contractors will require the work to be done as previously done by the employees of Carillion," he said.

"We can't give a cast-iron guarantee on the workers but I think there's a good chance that many of those will be re-employed and for those that are not we've offered assistance."

But Gordon Nelson, Scotland director of the Federation of Master Builders, said the “ripple effect” from Carillion’s collapse would affect hundreds of businesses in Scotland – with “huge repercussions” across the sector.

He added that “time would tell” if there will also be knock-on effects for large projects such as the £745m Aberdeen bypass.