The new HMP Highland, which will cost £209 million, will be able to accommodate 200 prisoners, over 100 more than the design capacity of HMP Inverness that it will replace.

Once completed in 2026, it will be Scotland’s first net-zero prison, with improved education and health facilities to help with rehabilitation. It will also allow more adult men from the Highlands and Islands to be accommodated in their local area, improving access for families and services.

The construction contract signed with Balfour Beatty will create more than £60m worth of supply chain investment with local businesses and new jobs both in the build and operation phases of the new prison.

However, the cost of the facility has risen from £92m, the figure given in 2020, and is now quadruple the original figure of £52m.

Justice secretary Angela Constance blamed the rising cost on Brexit, high inflation and supply chain issues.

Ms Constance said: “Signing this contract marks a significant milestone for the Highlands, which will not only provide much-needed additional capacity and continue the modernisation of Scotland’s prison estate but will also provide investment and jobs to the area.

“HMP Highland will deliver safe and secure accommodation with better education and health facilities to help with rehabilitation and reduce offending.

“As with all large-scale national construction projects, Brexit, high inflation and supply chain issues have had an impact on the initial estimated costs, which we have been working hard with the prison service and suppliers to keep to a minimum.”

Linda Pollock, deputy chief executive of the Scottish Prison Service, said: “With the support of the Scottish government, we are committed to investing in our estate to create better environments for people to live and work.

“HMP Highland will not only increase the capacity previously available at HMP Inverness, but also provide space for quality rehabilitative work which we know gives people the greatest possible chance of a successful return to their communities on liberation.”