The wooden beam came loose above MSPs in the chamber Enlarge Image

Engineers discovered that the bolt holding the oak beam had sheared, but so far have not found a cause.

The Health and Safety Executive has agreed the strut should be sent away to a testing centre in Hertfordshire.

The bolt and socket will be examined to verify whether other bolts in the chamber are sound. MSPs will continue to use the Hub venue next week.

The Holyrood debating chamber has more than 60 specially laminated and steel-reinforced oak beams, which each weigh around half-a-tonne and are held in place by steel nodes.

Key questions remain on cause, remedy and therefore resolution Scottish Parliament spokesman

One of the beams swung free on 2 March, almost crashing into a glass screen and ended up hanging 20ft above the Tory benches.

The Scottish Parliamentary Corporate Body (SPCB) has now considered reports on the situation from structural engineers Arup.

They recommended the beam be taken to an accredited testing house to enable the failed bolt and its socket to be removed for subsequent metallurgical testing.

The HSE agreed that the beam should be sent to Stanger Materials Science based in St Albans, Herts.

The beam will be wrapped in bubblewrap and then over-wrapped in heavy gauge polythene to be transported by road.

MSPs have had to go on the road to continue business

The SPCB has also received a report on the impact on parliamentary business and the options for alternative accommodation, which will be discussed next Tuesday.

A Scottish Parliament spokesman said: "Key questions remain on cause, remedy and therefore resolution.

"The chamber has to be back in business at Holyrood as quickly as possible, and then we will look at issues of liability of costs incurred to the public purse.

"We are not going to second-guess the work of the engineering experts or pre-empt the detail of their investigation.

"We will continue to release information as we receive it and consider further progress reports."